Nine new species of Meriania are described and illustrated and M. zunacensis, originally described from Ecuador, is recorded for the first time for Peru from Andean forests in the Amazonas Department. The new species are M. bicentenaria and M. vasquezii from Pasco, M. bongarana, M. callosa and M. juanjil from Amazonas, M. hirsuta from Piura, M. megaphylla from La Libertad, M. sumatika from Cusco and M. escalerensis from the Loreto-San Martín border. Following IUCN criteria, M. megaphylla is categorized as Data Deficient (DD) as it is only known from one collection made in 1914, M. bicentenaria and M. sumatika are categorized as Endangered (EN) and the remaining new species are categorized as Critically Endangered (CR). With these discoveries, N Peru (Departments of Amazonas, Cajamarca and Piura) harbours the highest number of Meriania species in the country. Also, Peru now has a total of 34 species of Meriania and is the country with the second highest diversity for the genus.
Citation: Fernandez-Hilario R., Rojas Gonzáles R. del P., Villanueva-Espinoza R., Lajo L., Wong Sato A. A., Paredes-Burneo D., Pillaca-Huacre L., Michelangeli F. A. & Goldenberg R. 2022: Nine new species and a new country record for Meriania (Melastomataceae) from Peru. – Willdenowia 52: 39–74.
Version of record first published online on 3 March 2022 ahead of inclusion in April 2022 issue.
Introduction
Meriania (Melastomataceae) was established by Swartz in 1798 based on collections from Jamaica. It currently comprises 121 species of shrubs, trees and occasionally climbers, distributed from SE Mexico and the Greater Antilles to E Brazil and Bolivia (Michelangeli & al. 2015; Michelangeli & al. 2020). Along with Adelobotrys DC., Axinaea Ruiz & Pav., Centronia D. Don, Graffenrieda DC., Macrocentrum Hook. f., Maguireanthus Wurdack and Salpinga Mart. ex DC., it forms the neotropical tribe Merianieae (Michelangeli & al. 2020), which can be recognized by the diplostemonous flowers, anthers with dorsal appendages, capsular fruits and predominantly pyramidal seeds (Renner 1993; Mendoza-Cifuentes & Fernández-Alonso 2010).
The genus is characterized by being trees and shrubs, occasionally climbers, lacking malpighiaceous trichomes, with an entire calyx, which can be lobed, subcalyptrate or calyptrate and with regular, irregular or circumscissile dehiscence, spreading to campanulate corollas and anthers usually with a dorsally inclined pore (Wurdack 1973, 1980, 1993; Michelangeli & al. 2015; Mendoza-Cifuentes 2021). In recent years, the exploration of the Andean forests (Michelangeli & Goldenberg 2018; Fernández-Fernández & al. 2020; Fernandez-Hilario & al. 2020a, 2021; Mendoza-Cifuentes 2021) and the Atlantic forest of Brazil (Goldenberg & al. 2016, 2020) has led to the discovery of many new species. Despite these breakthroughs, there are still many undescribed species, mainly due to the poor exploration and collection in some highly diverse regions (see Michelangeli & Goldenberg 2018).
The highest diversity of Meriania is recorded in Colombia (37 species, Mendoza-Cifuentes 2021) and Ecuador (31 species, Fernández-Fernández 2010). In Peru, the last revision of the genus was made by Macbride (1941), where he recognized 12 species. Since then, several publications have increased the number of recognized species to 24 through new descriptions and new records; 15 of these species have been recorded in the N Peruvian Andes (Departments of Amazonas, Cajamarca and Piura) (Brako & Zarucchi 1993; Cotton & al. 2014; Michelangeli & Goldenberg 2018; Paredes-Burneo & al. 2018; Fernandez-Hilario & al. 2020a, 2021).
As part of an ongoing taxonomic revision of Meriania for Peru, we present nine new species and a new country record. All of them were discovered during botanical expeditions in the Peruvian Andes and the study of herbarium material. We provide morphological descriptions along with comments on related species and diagnostic characteristics, conservation status and geographic distribution for each of the newly described species.
Material and methods
The descriptions were made through examination of herbarium specimens deposited in AMAZ, CPUN, CUZ, HOXA, HSP, HUT, KUELAP, MOL, NY, UPCB and USM (herbarium codes follow Thiers 2020+). Additionally, specimens from digital collections at F ( https://collections-botany.fieldmuseum.org/), P ( https://science.mnhn.fr/) and US ( https://collections.nmnh.si.edu/search/botany/) were consulted. Indumentum terminology, trichome classification and fruit type follow Beentje (2010), Wurdack (1986) and Baumgratz (1983–1985), respectively. For the description of inflorescences, we considered “few-flowered”, “submultiflorous” and “multiflorous” as inflorescences with fewer than 25 flowers, with 25–60 flowers and with more than 60 flowers, respectively. The description and measurement of flowers is based on rehydrated material (Meriania bicentenaria, M. escalerensis, M. hirsuta, M. megaphylla, M. juanjil and M. sumatika) or material fixed in 50–70 % ethanol (M. bongarana, M. callosa, M. vasquezii and M. zunacensis). Information on colours of floral parts is derived from our own field observations supplemented by label information and photographs provided by collaborators. Thecae surfaces are described as smooth or corrugated; the latter condition refers to polysporangiate anthers (see Caetano & al. 2020). A complete description is provided for the new record of M. zunacensis for Peru as these additional specimens provide not only a range extension, but also some additional character variability.
A morphological species concept has been used in this study, which establishes that consistent differences in morphology, resulting in discrete entities, are considered evidence of the existence of separate species (see Judd 2007). The combination of several discontinuous morphological characters was used to recognize the new species. Comments on the distribution and morphological differences among Andean species of Meriania were made based on checklists and taxonomic treatments for Bolivia (Jørgensen & al. 2014), Colombia (Almeda & al. 2020; Mendoza-Cifuentes 2021), Ecuador (Wurdack 1980; Jørgensen & León-Yáñez 1999), Peru (Macbride 1941; Brako & Zarucchi 1993) and Venezuela (Wurdack 1973; Hokche & al. 2008) and examination of the protologues of recently described Meriania species and type specimens available through JSTOR Global Plants Initiative portal ( https://plants.jstor.org/). The distribution maps were made in software QGIS version 3.18.1 (QGIS Development Team 2021). Conservation status for the new species was assigned using IUCN criteria (2012, 2019), based on estimates of Extent of Occurrence (EOO) and Area of Occupancy (AOO), both calculated through GeoCat Geospatial Conservation Assessment Tool ( http://geocat.kew.org/) (Bachman & al. 2011).
Taxonomic treatment
New species
1. Meriania bicentenaria Rob. Fern., R. Rojas & Michelang., sp. nov. – Fig. 1–3.
Holotype: Peru, Pasco, Prov. Oxapampa, Dist. Oxapampa, Abra Oxapampa-Villa Rica, 10°40′36″S, 75°18′55″W, 2300–2500 m, 6 Aug 2004 (fl., fr.), R. Vásquez, A. Monteagudo, L. Valenzuela, J. Perea & A. Peña 30366 (HOXA accession no. 10648!; isotypes: NY barcode 03785787!, USM accession no. 215491!).
Diagnosis — A species differing from other congeners by the combination of roughened to dendritic trichomes evenly covering the abaxial surface of leaves, calyces with rounded lobes and without dorsal projections, campanulate, deep pink corollas, strongly dimorphic stamens, stamen connectives with acuminate to falcate, descending dorsobasal appendages and antipetalous stamens with inflated connectives.
Morphological description — Tree up to 35 m tall and 50 cm d.b.h.; young branches and petioles puberulent with roughened to dendritic trichomes up to 0.13 mm long, sparsely to moderately on young branches, moderately to densely on petioles. Young branches terete, 4–6 mm in diam., lacking wings, nodes without interpetiolar flaps. Leaves opposite, isophyllous, sometimes slightly anisophyllous. Petioles terete, 2.4–6 cm, with an adaxial projection (scutum) at insertion of petiole with leaf blade, up to 0.5 mm high, sometimes inconspicuous or obscured by trichomes. Leaf blades coriaceous, 10–18.9 × (2.9–)5–8.4 cm, elliptic to slightly lanceolate, sometimes broadly elliptic, apex acute, rarely obtuse, base obtuse to rounded, margin entire, discolorous; venation acrodromous and basal, with one pair of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 33–48 on each side of primary, percurrent, 1–7 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation barely visible on abaxial surface; adaxial surface flat, brown, glabrous or sparsely puberulent with roughened to dendritic trichomes, denser near base, up to 0.13 mm long; abaxial surface light brown, midvein, secondary veins, tertiary veins, reticulation and surface densely pubescent with roughened to dendritic trichomes up to 0.13 mm long, evenly covering entire surface. Inflorescences terminal panicles, erect, 15.6–30 × 6.7–17 cm, multiflorous; axis and peduncle moderately puberulent with trichomes similar to ones on twigs and petioles. Peduncle 4.8–8.2 cm long, terete. Main axis 7.5–16.5 cm, terete. Paraclades in 5–7 pairs, proximal 5.9–11 cm long, distal 1.8–2.8 cm long; flowers in 4-flowered umbels at ends of branchlets. Bracts foliaceous, persistent, 10.6–16 × 4.3–6.5 cm, petioles 3.2–7.3 cm long, shape and indumentum similar to principal leaves. Bracteoles not seen (probably early caducous). Flowers (4 or)5-merous, with campanulate corollas. Pedicels 3.5–6 mm long, greenish to light purple, moderately puberulent with trichomes similar to ones on inflorescence axis. Hypanthium 3–4 × 5.5–7.5 mm, campanulate, greenish to light purple, outer surface sparsely to moderately puberulent with trichomes up to 0.13 mm long, similar to those on pedicels, inner surface glabrous to sparsely puberulent with trichomes similar to those on pedicels; torus glabrous. Calyx opening regularly, greenish to light purple, outer surface glabrous to sparsely puberulent with trichomes up to 0.13 mm long, similar to ones on pedicels, inner surface glabrous; tube 1–1.5 mm long; lobes 1–1.5 mm long, 3–5 mm wide at base, rounded, without dorsal projections. Petals 11.5–13.5 × 7–9 mm, 3.5–4 mm wide at base, oblong, apex asymmetric, margin entire, deep pink, apex sometimes slightly ciliate. Stamens (8–)10, strongly dimorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; antisepalous stamens with filaments 5–6 mm long, deep pink, flat, glabrous, connectives not prolonged below thecae, dark purple, glabrous, with two appendages, one descending dorsobasal, 3–4 mm long, acuminate, dark purple, other dorsal appendage a mere hump or inconspicuous, c. 0.25 mm long, broadly rounded, dark purple, 4 mm from tip of descending dorsobasal appendage, anthers 4–5 mm long, lanceolate, purple, glabrous, slightly curved, opening by one dorsally inclined pore, thecae with a smooth surface; antipetalous stamens with filaments 5–6 mm long, deep pink, flat, glabrous, connectives prolonged below thecae c. 0.25 mm long (not including descending dorsobasal appendage), abruptly inflated from 1–1.5 mm of tip of thecae, purple at apex, cream in first half of inflated portion and light purple in second half of inflated portion, glabrous, with one descending dorsobasal appendage, 3–4.5 mm long, falcate, dark purple, anthers 4.5–5 mm long, lanceolate, purple, glabrous, slightly curved, opening by one dorsally inclined pore, thecae surface smooth. Ovary (4 or)5-locular, superior, 3–3.5 × 3–4 mm, spheroid and slightly 5-costate, pink, not exceeding hypanthium length, glabrous; style 11.5–16 mm long, pink, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.5 mm wide, deep pink. Fruits capsular (velatidia), with persistent hypanthium and calyx; mature ovary 5 × 5.5 mm, spheroid, slightly costate, 1.5 mm exceeding hypanthium length; fruiting pedicels 5–8 cm long. Seeds triangular-linear, c. 0.5 mm long, numerous.
Fig. 1.
Meriania bicentenaria – A: terminal fertile branch with inflorescence; B: detail of leaf base, adaxial surface; C: detail of abaxial leaf surface; D: petal; E: antisepalous stamen, lateral view; F: antipetalous stamen, lateral view; G: flower with petals removed. – A–C from A. Monteagudo & al. 6960; D–G from R. Villanueva-Espinoza 675.
Fig. 2.
Meriania bicentenaria – A: terminal fertile branch; B: leaf blade, abaxial view; C: flower at anthesis, lateral view; D: flower at anthesis, apical view. – From R. Villanueva-Espinoza 675. – Photographs by Rosa Villanueva-Espinoza.
Phenology — Flowering occurs from June to September and fruiting from March to November.
Distribution and ecology — Meriania bicentenaria is endemic to high-elevation montane forests in the Department of Pasco, between 2200 and 2550 m. Populations of this species usually occur in pristine forests and seldom in disturbed forests.
Conservation status — Meriania bicentenaria is known from five localities, growing in surroundings of the Yanachaga-Chemillén National Park. Following IUCN (2012, 2019) guidelines and based on an estimated extent of occurrence of 304 km2, we recommend the category Endangered EN B1ab(iii) for this species.
Etymology — The specific epithet commemorates the 200th anniversary of the Independence of Peru (1821–2021).
Discussion — Meriania bicentenaria belongs to the M. macrophylla complex (Wurdack 1978; Ulloa Ulloa & Homeier 2008), which is characterized by campanulate corollas, strongly dimorphic stamens and antipetalous stamens with inflated connectives. The M. macrophylla complex comprises six species distributed from S Mexico (state of Chiapas) to NW South America (Colombia, Ecuador, Peru and Venezuela) (Wurdack 1978; Almeda 1993; Ulloa Ulloa & Homeier 2008; Bussmann & Paniagua 2012; Almeda & al. 2020; Fernandez-Hilario & al. 2021).
Meriania bicentenaria, M. franciscana C. Ulloa & Homeier and M. ninakurorum (Bussmann & Paniagua) E. Cotton & Balslev are the only species of M. macrophylla complex occurring in Peru. Meriania bicentenaria occurs in central Peru (Department of Pasco), while the other two species occur in the N part of the country in the Departments of Cajamarca (M. franciscana) and San Martín (M. ninakurorum). These species are also the only ones within the complex that lack stamen connectives with descending bifid dorsobasal appendages. Meriania bicentenaria shares with M. ninakurorum the antipetalous stamen connectives without ascending appendages. Nevertheless, M. bicentenaria is distinguished from M. ninakurorum by the petioles with projections (scutum) (vs without projections in M. ninakurorum) and leaf blades 10–18.9 × (2.9–)5–8.4 cm (vs 23–32 × 9–15 cm). In addition, M. bicentenaria shares with M. franciscana the presence of an adaxial projection (scutum) at the insertion of the petiole with the leaf blade and roughened to dendritic trichomes on abaxial leaf surfaces. However, M. bicentenaria differs from M. franciscana by its leaf blades with entire flat margins (vs often slightly revolute at the base), abaxial leaf surface densely pubescent evenly covering the entire surface (vs sparsely to densely puberulent but without covering the entire surface), deep pink petals (vs reddish purple) and antipetalous stamen connectives without ascending appendages (vs with blunt ascending appendages).
Additional specimens examined (paratypes) — Peru: Pasco, Prov. Oxapampa, Dist. Palcazú, without locality, 10°32′S, 75°23′W, 2200 m, 4 Oct 1984 (fr.), D. Smith & al. 8685 (F!); Dist. Oxapampa, camino a la Cordillera Yanachaga, 10°23′S, 75°27′W, 2400 m, 19 Jul 1984 (fr.), D. Smith & al. 7913 (F!, US!, USM!); camino Oxapampa-Abra Villa Rica, 10°39′23″S, 75°20′27″W, 2270 m, 10 Aug 2004 (fl.), A. Monteagudo & al. 6960 (HOXA!, NY!); camino Oxapampa-Villa Rica, km 37 en zona de amortiguamiento, 10°38′12″S, 75°24′45″W, 2462 m, 15 Mar 2006 (sterile), S. Vilca & al. 643 (HOXA!, USM!); Cuenca del río San Alberto, 10°32′39.90″S, 75°22′13.63″W, 2286 m, 1 Oct 2019 (sterile), C. Llerena 23 (MOL!); same locality and data (fr.), C. Llerena 32 (MOL!); CDS, Sector San Alberto – Entrada al Parque Nacional Yanachaga Chemillén, 10°32′25″S, 75°22′14″W, 2290 m, 10 Jun 2021 (fl.), R. Villanueva-Espinoza 675 (MOL!); Parque Nacional Yanachaga Chemillén, 10°32′S, 75°21′W, 2420 m, 26 Aug 2002 (fl., fr.), A. Monteagudo & al. 3807 (AMAZ!, MOL!, NY!); Parque Nacional Yanachaga-Chemillén, cercanías del Refugio el Cedro, 10°32′51″S, 75°21′32″W, 2420 m, 26 Aug 2002 (fl., fr.), A. Monteagudo & al. 3808-A (HOXA!); San Alberto, 10°32′43.54″S, 75°21′37.14″W, 2457 m, 24 Mar 2014 (sterile), R. Tupayachi & al. 13589 (HSP!); San Alberto, 10°32′41.47″S, 75°20′29.34″W, 22457 m, 5 Mar 2014 (sterile), R. Tupayachi & al. 13601 (HSP!); Sector San Alberto, 10°32′45″S, 75°21′24″W, 2468 m, 17 Aug 2006 (fr.), L. Cárdenas & al. 715 (CUZ!, HOXA!, MOL!, USM!); PN Yanachaga-Chemillén, Sector San Alberto, zona de amortiguamiento, 10°19′S, 75°13′W, 2450 m, 16 Mar 2005 (fr.), R. Rojas & al. 3539 (HOXA!, NY!); Dist. Huancabamba, PN Yanachaga Chemillén, Fundo Osobamba, 10°23′34.7″S, 75°28′28.1″W, 2243 m, 25 Jun 2016 (fl.), L. Valenzuela & al. 30395 (USM!); Grapanazu, sector San Daniel, zona de amortiguamiento del PN Yanachaga-Chemillén, 10°26′36″S, 75°26′21″W, 2236 m, 8 Jul 2004 (fl.), J. Perea & al. 1445 (HOXA!, NY!); same locality and data (fl.), J. Perea & al. 1449 (HOXA!, NY!); same locality, 10 Jul 2004 (fl., fr.), J. Perea & al. 1467 (HOXA!, NY!); Acuzazu, 10°30′24″S, 75°23′13″W, 2200–2300 m, 6 Jul 2004 (fl., fr.), R. Rojas & al. 3132 (HOXA!, NY!); PN Yanachaga Chemillen, Sector Quebrada Yanachaga, 10°23′45″S, 75°28′55″W, 2300 m, 19 Aug 2004 (fl.), R. Vásquez & al. 30410 (HOXA!, NY!, USM!); same locality and data (fl.), R. Vásquez & al. 30419 (HOXA!); same locality, 10°23′38″S, 75°28′36″W, 2407 m, 20 Sep 2004 (fl., fr.), J. Perea & J. Mateo 1781 (HOXA!, NY!); PN Yanachaga-Chemillen, parcela permanente 1.0 ha Oso Playa, 10°17′58″S, 75°36′35″W, 2200 m, 11 Nov 2006 (fr.), A. Monteagudo & al. 13406 (NY!, USM!); Torre Bamba, 10°18′24″S, 75°35′06″W, 2550 m, 20 May 2004 (fr.), R. Rojas & al. 2403 (HOXA!).
2. Meriania bongarana Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 4–6.
Holotype: Peru, Amazonas, Prov. Bongará, Dist. Yambrasbamba, Inmediaciones de la Estación Biologica Abra Patricia, 05°41′32.91″S, 77°48′41.1″W, 2320 m, 19–20 Feb 2020 (fl., fr.), R. Fernandez-Hilario, R. Villanueva & L. Pillaca 1930 (MOL barcode 000006!; isotypes: CUZ!, HOXA accession no. 077852!, NY barcode 04239398!, UPCB accession no. 99400!).
Diagnosis — A species differing from other congeners by the combination of ferruginous indumentum evenly covering the abaxial surface of leaves, calyx lobes with claw-shaped dorsal projections (1.5–2.5 mm long), campanulate, pink-orange corollas, isomorphic stamens, stamen connectives prolonged below the thecae and with a slightly crown-shaped descending dorsobasal appendage.
Morphological description — Tree up to 5 m tall; young branches and petioles pubescent with sessile stellate trichomes, these up to 0.10 mm long, moderately to densely on young branches, densely on petioles. Young branches terete-quadrangular, 5–6 mm in diam., lacking wings, nodes without interpetiolar flaps. Leaves opposite, isophyllous. Petioles terete, 1.2–1.5 cm long, without projections. Leaf blades coriaceous, 7.5–9.5 × 3.2–4.3 cm, elliptic, apex acuminate, base acute, margin finely serrulate on distal half to two-thirds, discolorous; venation acrodromous and suprabasal, with one pair of secondaries (lateral nerves), diverging 3–4 mm from base of blade and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 31–33 on each side of primary, percurrent, 1.5–3.5 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation visible on abaxial surface; adaxial surface flat, light olive to olive-green when dry, glabrous; abaxial surface ferruginous when dry, densely pubescent with sessile stellate trichomes intermixed with elongated trichomes with greatly roughened base, up to 0.5 mm, evenly covering entire surface, with pocket domatia at convergence of midvein and secondary veins. Inflorescences terminal panicles, erect, 7.5–8.2 × 6.8–7 cm, submultiflorous; axis and peduncle densely pubescent with trichomes similar to ones on abaxial surface of leaves, longer (up to 1 mm long) on nodes. Peduncle 2–2.2 cm long, terete-quadrangular. Main axis 3.5–4.8 cm long, terete-quadrangular, with 2–3 pairs of proximal paraclades and two nodes, subdistal node with 4 flowers, distal node with an umbel. Paraclades in one proximal pair, 3.7–4.2 cm long; flowers in 4- or 5-flowered umbels at ends of branchlets. Bracts foliaceous, persistent, 8–9.7 × 3.5–4.2 cm, petioles 1.5–1.8 cm long, shape and indumentum similar to principal leaves; sometimes with one pair of additional bracts on paraclades of main axis, 5.5 × 6.8 cm, petioles 1.2–1.7 cm long. Bracteoles not seen (probably early caducous). Flowers 5-merous, pendant, with campanulate corollas. Pedicels 7–9 mm long, ferruginous, densely pubescent with trichomes similar to ones on inflorescence axis, up to 0.75 mm. Hypanthium 6.5–7 × 4.5 mm, campanulate, ferruginous, outer surface pubescent with trichomes similar to ones on pedicels, inner surface glabrous; torus glabrous. Calyx opening regularly, ferruginous, outer surface densely pubescent with trichomes similar to ones on pedicels, inner surface glabrous; tube 2–2.5 mm long; lobes 2–2.5 × 5–7 mm, acute, each with a claw-shaped dorsal projection, 2–3 mm long. Petals 14–15.5 × 13–16 mm, 3–3.5 mm wide at base, obovate and slightly asymmetric, apex rounded, margin entire, pink-orange, glabrous. Stamens 10, isomorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; filaments 8–8.5 mm, pink to magenta, semiterete, glabrous; connectives prolonged below thecae 1 mm (not including descending dorsobasal appendage), magenta, glabrous, with one descending dorsobasal appendage, c. 1 mm long, slightly crown-shaped, with rounded to irregular lobes up to 0.13 mm; anthers 8.5–9 mm long, lanceolate, magenta, glabrous, with its apical third slightly inflexed, opening by one dorsally inclined pore, thecae surface slightly corrugated. Ovary 5- or 6-locular, superior, basally fused with hypanthium, free portion c. 5 × 3.5 mm, ovate and slightly 5- or 6-costate, magenta, not exceeding hypanthium length, glabrous; style 25.5–27 mm long, magenta, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.75 mm wide, whitish. Fruits capsular (velatidia), with a persistent hypanthium and caducous calyx; mature ovary c. 7 × 6.5 mm, spheroid, slightly costate, completely concealed by hypanthium; fruiting pedicels 15–17 mm long. Seeds triangular-linear, c. 0.75 mm long, numerous.
Fig. 4.
Meriania bongarana – A: terminal fertile branch with inflorescence with detail of leaf margin; B: inflorescence branch; C: flower at anthesis, lateral view; D: petal; E: stamen, lateral view; F: ovary and style; G: hypanthium and calyx, longitudinal section. – A–D from R. Fernandez-Hilario & al. 1930. – Drawing by Leticia Lajo.
Fig. 5.
Meriania bongarana – A: leaf blade, abaxial view; B: inflorescence with flower buds; C: terminal fertile branch with inflorescence; D: fruits. – A–D from R. Fernandez-Hilario & al. 1930. – Photographs by Robin Fernandez.
Phenology — Flowering and fruiting occur in February.
Distribution and ecology — Meriania bongarana is a Peruvian endemic known from a single locality in the Abra Patricia Conservation Area in the Department of Amazonas, on moderate slopes at 2320 m. At this locality, M. bongarana occurs in undisturbed forests.
Conservation status — The only locality recorded for Meriania bongarana is located between two protected areas, Alto Mayo Protection Forest and Nieva River Reserved Zone. However, the pristine forests in Bongará province are decreasing due to the expansion of agriculture and livestock. Despite being a little-explored region in Amazonas, several endemic species have been discovered in Bongará province in recent years (e.g. Fernandez-Hilario & al. 2020b; Fernandez-Hilario & al. 2021; Tejedor & Calatayud 2017). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 4 km2, we recommend the category Critically Endangered CR B2ab(iii) for this species.
Etymology — The specific epithet refers to Bongará province (Department of Amazonas) in N Peru.
Discussion — Meriania bongarana belongs to a group of species characterized by campanulate, reddish orange corollas, and calyx lobes usually with claw-shaped to falcate dorsal projections. The species of this group occur in the Andes from Venezuela to N Peru. Meriania dazae Rob. Fern. & al. and M. bongarana are the only species in this group recorded for Peru. Within this group the most similar species to M. bongarana are M. cuneifolia Gleason, M. furvanthera Wurdack and M. stellata (Gleason) Wurdack, all endemic to Ecuador. However, M. bongarana differs from the first by its hypanthia 6.5–7 mm long (vs 4–5 mm in M. cuneifolia), petals 14–15.5 mm long (vs 10–13.5 mm), isomorphic stamens (vs dimorphic in size) and connectives prolonged below the thecae 1 mm (vs prolonged 1.3–1.7 mm). It differs from the second by its hypanthia terete (vs obscurely ribbed in M. furvanthera), calyx lobes with dorsal projections 2–3 mm long (vs c. 0.5 mm) and petals 14–15.5 mm long (vs 21–22.5 mm). It differs from the third by its inflorescences and hypanthia densely pubescent (vs densely villose in M. stellata), hypanthia terete (vs obscurely ribbed), isomorphic stamens (vs dimorphic in size) and stamen connectives with descending dorsobasal appendages c. 1 mm long (vs 0.25–0.4 mm).
The only Peruvian species with features similar to Meriania bongarana is M. dazae. Both species can be distinguished by the colour of the leaf blades on the abaxial surface (ferruginous in M. bongarana vs whitish to cream in M. dazae), petal length (14–15.5 mm vs 19.5–24 mm) and the dorsal appendages of stamen connectives (absent vs a mere hump, 0.25 mm long). Other Peruvian species such as M. acida (Markgr.) Wurdack and M. tomentosa (Cogn.) Wurdack can be confused with M. bongarana because they share the campanulate, pink-orange to reddish orange corollas. However, these two species have calyptrate calyces without dorsal projections (vs lobed calyces with falcate dorsal projections in M. bongarana) and with irregular dehiscence (vs regular dehiscence). Furthermore, M. bongarana differs from M. acida by the size of the leaf blades (7.5–9.5 × 3.2–4.3 cm vs 12–18 × 5–9 cm), inflorescence position (terminal vs pseudolateral) and petal size (14–15.5 mm long vs 10 mm long). Meriania bongarana differs from M. tomentosa by its inflorescences 7.5–8.2 cm long (vs 19.9–32.3 cm), stamen connectives with crown-shaped descending dorsobasal appendages (vs blunt) and magenta thecae (vs cream).
3. Meriania callosa Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 7–9.
Holotype: Peru, Amazonas, Prov. Bongará, Dist. Yambrasbamba, ruta desde CP Santa Rosa hacia bosque El Toro, 05°40′07.98″S, 77°55′30.04″W, 1950 m, 11 Nov 2020 (fl.), R. Fernandez-Hilario, W. Chuquitucto & A. Wong 2055 (MOL barcode 000007!; isotypes: HOXA accession no. 077833!, KUELAP accession no. 971!, MOL barcode 000008!, NY barcode 04239399!, UPCB accession no. 99412!).
Diagnosis — A species differing from other congeners by the combination of nodes with interpetiolar flaps (0.5–3 mm long), glabrous hypanthia and calyces, calyces with callose dorsal projections, spreading, deep pink corollas, isomorphic stamens, stamen connectives with two appendages, one triangular descending dorsobasal appendage and the other dorsal appendage a mere hump, and spheroid mature ovaries.
Morphological description — Tree up to 18 m tall; young branches and petioles glabrous. Young branches obscurely quadrangular, lacking wings, nodes with interpetiolar flaps, 0.5–3 mm long. Leaves opposite, isophyllous to slightly anisophyllous. Petioles semiterete and adaxially slightly ribbed, 10–22 mm long, without projections. Leaf blades coriaceous, 11–16 × 6.8–10.4 cm, elliptic to oblong, rarely ovate, apex acute to acuminate, base obtuse to rounded, sometimes slightly revolute at base, margin entire, concolorous; venations acrodromous and basal, with one or two pairs of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 30–42 on each side of primary, percurrent, 1–11.5 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation impressed on abaxial surface; adaxial surface flat, yellowish brown, glabrous; abaxial surface yellowish brown, glabrous to sparsely puberulent with short trichomes up to 0.10 mm long. Inflorescences terminal panicles, erect, 14–27.5 × 10–20 cm, few-flowered or submultiflorous; axis and peduncles glabrous. Peduncle 2.4–12.3 cm, quadrangular. Main axis 6–12.5 cm, quadrangular. Paraclades in 3–4 pairs, proximal 6–16.5 cm long, distal 2–3.5 cm long; flowers in regular dichasia at ends of branchlets. Bracts foliaceous, persistent, sometimes caducous, 12–18.2 × 9.2–11.2 cm, petioles 12–25 mm long, shape and indumentum similar to principal leaves; sometimes with one pair of additional bracts on subproximal nodes of main axis, 12.5–16 × 2.5–8.8 cm, petioles of these 1.5–2 cm long. Bracteoles foliaceous, caducous, 35–36 × 2.5–4 mm, elliptic, petioles 5–6 mm long, indumentum similar to ones on bracts. Flowers 5-merous, with spreading corollas. Pedicels 5–7 mm long, green, glabrous. Hypanthium c. 8.5 × 19 mm, campanulate, green, outer and inner surfaces glabrous; torus glabrous. Calyx opening regularly, green, outer and inner surfaces glabrous; tube 6–7 mm long; lobes repand; with 5 callose dorsal projections, forming irregularly square light green spots, much darker than rest of calyx and hypanthium when dry. Petals 44 × 38–40 mm, 8 mm wide at base, strongly asymmetric obovate, apex rounded, margin entire, deep pink, glabrous. Stamens 10, isomorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; filaments 18–19 mm, purple, flat, glabrous; connectives not prolonged below thecae, dark purple in thecae, glabrous, with two appendages, one descending dorsobasal, 5.5–6 mm long, triangular, yellow, other dorsal appendage a mere hump, c. 0.25 mm long, rarely inconspicuous, acute, dark purple, 5.5–5.8 mm from tip of descending dorsobasal appendage; anthers 13–14 mm long, lanceolate, dark purple, glabrous, straight, opening by one dorsally inclined pore, thecae surface smooth. Ovary 5-locular, superior, basally fused with hypanthium, free portion c. 7.5 × 7 mm, ovoid and slightly 5-lobed, light purple, 2.5 mm exceeding hypanthium length, glabrous; style c. 19.5 mm long, light purple, glabrous, incurved at apex and opposite anthers at anthesis; stigma punctiform and minutely papillate, 1 mm wide, cream. Fruits capsular (velatidia), with persistent hypanthium and calyx; mature ovary c. 11 × 11–12 mm, spheroid, 4–8 mm exceeding hypanthium length; fruiting pedicels 11.5 mm long. Seeds triangular-linear, c. 1.25 mm long, numerous.
Fig. 7.
Meriania callosa – A: terminal fertile branch with inflorescence with detail of interpetiolar flap; B: flower at anthesis, apical view; C: flower bud; D: petal; E: stamen, lateral view; F: fruit, lateral view; G: longitudinal section of flower with petals and stamens removed. – A–G from R. Fernandez-Hilario & al. 2055. – Drawing by Leticia Lajo.
Fig. 8.
Meriania callosa – A: leaf blade, abaxial view; B: inflorescence with flower buds; C: flower at anthesis, lateral view; D: flower at anthesis, apical view. – A–D from R. Fernandez-Hilario & al. 2055. – Photographs by Robin Fernandez.
Phenology — Flowering occurs in April and November and fruiting in August and November.
Distribution and ecology — Meriania callosa is endemic to high-elevation montane forests in the Districts of Mariscal Benavides and Yambrasbamba (Amazonas, Peru), between 1880 and 1970 m, on moderately to strongly sloping terrain. Common tree species at this locality “CP Santa Rosa” (Fernandez-Hilario & al. 2055, 2056) include Alzatea verticillata Ruiz & Pav. (Alzateaceae), Cecropia angustifolia Trécul (Urticaceae), Ficus mutisii Dugand (Moraceae), Graffenrieda emarginata Triana (Melastomataceae), M. penningtonii Rob. Fern. & al. (Melastomataceae) and Ladenbergia riveroana Standl. (Rubiaceae).
Conservation status — Meriania callosa is known from two localities, the CP Santa Rosa and the CP Izcuchaca, both located outside protected areas or conservation areas. In both localities, the forests are fragmented due to the recent increase of deforestation for agriculture and livestock. Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 8 km2, we recommend the category Critically Endangered CR B2ab(iii) for this species.
Etymology — The specific epithet refers to the presence of callose dorsal projections on the calyx of this species.
Discussion — Meriania callosa is distinguished from other congeners by the combination of nodes with interpetiolar flaps (0.5–3 mm long), glabrous flowers, spreading, deep pink corollas, calyces with callose dorsal projections and isomorphic stamens. The callose dorsal projections on the calyx are an unusual feature within Meriania, although some species such as M. hernandi L. Uribe, M. tetragona (Cogn.) Wurdack, M. sanguinea Wurdack may have them. In these species, the projections are less conspicuous and often difficult to see in herbarium material. In addition, M. hernandi (Ecuador and Colombia) has spreading, orange corollas and M. sanguinea (from Colombia to Peru) and M. tetragona (Ecuador and Peru) have campanulate, deep red corollas. Meriania penningtonii also has callose dorsal projections and grows sympatrically with M. callosa. However, the projections in both species are different, these being small and whitish in M. penningtonii (see fig. 3C, D in Fernandez & al. 2021) while in M. callosa they are light green and cover a large part of the calyx. Additionally, M. penningtonii has winged internodes (vs internodes without projections in M. callosa) and bullate leaves (vs flat). Another species with similar dorsal projections on the calyx is M. fantastica Alvear & al. (Colombia), although in this species the callose projections are much more evident than in M. callosa (see fig. 4B in Mendoza-Cifuentes & al. 2014). Meriania callosa is distinguished from M. fantastica by leaf blade size (11–16 × 6.8–10.4 cm vs 15.5–31 × 10.4–20 cm), petal colour (deep pink vs orange) and relative stamen size (isomorphic vs dimorphic in size).
Among Peruvian species, Meriania callosa resembles M. megaphylla (also described here) and M. zunacensis D. Fernández & Dellinger (also in Ecuador). All of them have interpetiolar flaps and spreading corollas, but M. callosa differs from the others by lacking projections at the insertion of the petioles with the leaf blade. Meriania callosa also differs from M. megaphylla by its obscurely quadrangular internodes (vs quadrangular and 4-winged in M. megaphylla), leaf blades 11–16 × 6.8–10.4 cm with obtuse to rounded bases (vs 21–29.4 × 14.8–22 cm with cordate base), hypanthia c. 8.5 × 19 mm (vs 4.5–5 × 4–4.5 mm) and stamen connectives with dorsal appendages as mere humps (vs blunt, ascending); it differs from M. zunacensis by its leaf blades with entire flat margins (vs revolute at the base in M. zunacensis), flowers at the ends of branchlets arranged in regular dichasia (vs 4- or 5-flowered umbels), ovary c. 7.5 × 7 mm (vs 13–14.5 × 7–7.5 mm), spheroid when mature (vs pyriform).
Additional specimens examined (paratypes) — Peru: Amazonas, Prov. Bongará, Dist. Yambrasbamba, ruta desde CP Santa Rosa hacia bosque El Toro, 05°40′09.22″S, 77°55′30.05″W, 1970 m, 11 Nov 2020 (fl. bud, fr.), R. Fernandez-Hilario & al. 2056 (HOXA!, MOL!, NY!, UPCB!); Prov. Rodríguez de Mendoza, Dist. Mariscal Benavides, CP Izcuchaca, 06°19′40″S, 77°31′05″W, 1880 m, 30 Aug 1998 (fr.), R. Vásquez & J. Campos 25339 (NY!); same locality, 11 Apr 2001 (fl.), H. van der Werff & al. 16941 (NY!, USM!).
4. Meriania escalerensis Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 9–11.
Holotype: Peru, Loreto, Prov. Alto Amazonas, Dist. Balsapuerto, Cordillera Escalera, Campamento Cumbre – Alto Cachiyacu, 05°52′02.1″S, 76°46′29.3″W, 1930 m, 22 Sep 2013 (fl.), M. Ríos, T. Mori, D. Neill, L. Torres & C. Vriesendorp 3316 (AMAZ!; isotypes: F accession no. 2323926!, USM accession no. 287375!).
Diagnosis — A species differing from other congeners by the combination of ferruginous indumentum, calyptrate calyces with circumscissile dehiscence, spreading, deep pink corollas, isomorphic stamens, and stamen connectives with two appendages, one triangular descending dorsobasal appendage and the other blunt ascending dorsal appendage.
Morphological description — Small tree up to 4 m tall; young branches and petioles densely setulose with conic densely roughened trichomes up to 0.3 mm long. Young branches quadrangular, 5–5.5 mm in diam., lacking wings, nodes without interpetiolar flaps. Leaves opposite, isophyllous to slightly anisophyllous. Petioles semiterete, 1.2–2.2 cm long, without projections. Leaf blades coriaceous, 13.3–15.5 × 7.6–8.8 cm, ovate to lanceolate, apex acute to obtuse, base cordate, margin moderately denticulate on distal two-thirds, slightly discolorous; venation acrodromous and basal, with two pairs of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 30–41 on each side of primary, percurrent, 1.5–7 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation visible on abaxial surface; adaxial surface flat, golden brown when dry, glabrous to sparsely setulose on veins with similar trichomes to ones on petioles; abaxial surface light golden brown when dry, midvein and secondary veins densely setulose, tertiary veins, reticulations and surface sparsely to moderately setulose, with trichomes similar to ones on petioles, denser on veins. Inflorescences terminal panicles, erect, c. 22 × 14 cm, submultiflorous or multiflorous; axis and peduncle densely setulose with trichomes similar to ones on terminal twigs, longer (up to 0.75 mm long) on nodes. Peduncle 4.5–7 cm long, quadrangular. Main axis 15.7–16.5 cm, quadrangular. Paraclades in 6 pairs, proximal 9–10 cm long, distal 2.2–2.5 cm long; flowers in regular dichasia at ends of branchlets. Bracts foliaceous, persistent or caducous, 2.9 × 0.9 cm, elliptic, petioles 7.5–8 mm long, indumentum denser than ones on leaves. Bracteoles not seen (probably early caducous). Flowers 5-merous, erect, with spreading corollas. Pedicels 2.5–3 mm long, ferruginous, densely setulose with trichomes similar to ones on peduncle and axis up to 0.3 mm long. Hypanthium c. 4.5 × 7 mm, campanulate, ferruginous, outer surface densely setulose with trichomes similar to ones on pedicels, inner surface glabrous; torus glabrous. Calyx with circumscissile dehiscence, ferruginous, outer surface densely setulose with trichomes similar to ones on pedicels, inner surface glabrous; calyx lobes fused, forming a calyptra, 8–9.5 mm long, conic and acuminate, without dorsal projections. Petals c. 21 × 14 mm, c. 2.5 mm wide at base, obovate, apex rounded, margin entire, pink, glabrous. Stamens 10, isomorphic, all bent to one side of flower giving flower a zygomorphic appearance; filaments c. 8.5 mm long, pink, flat, glabrous; connectives not prolonged below thecae, light purple in distal half of thecae, cream in proximal half of thecae, with two appendages, one descending dorsobasal, c. 3.75 mm long, triangular, cream, other ascending dorsal appendage, c. 0.75 mm long, blunt, cream, 3–3.5 mm from tip of descending dorsobasal appendage; anthers c. 7.5 mm long, lanceolate, magenta on apex and cream to base, glabrous, straight, opening by one dorsally inclined pore, thecae surface corrugated. Ovary 5-locular, superior, c. 5 × 4–4.5 mm, ovate and 10-lobed, with an apical ring of 10 teeth, 1 mm long, pink, c. 1 mm exceeding hypanthium length, glabrous; style c. 10 mm long, pink, glabrous, slightly incurved at apex and opposite anthers at anthesis; stigma punctiform and minutely papillate, c. 0.4 mm wide, whitish. Fruits and seeds not seen.
Fig. 10.
Meriania escalerensis – A: terminal fertile branch with inflorescence; B: detail of abaxial leaf surface; C: detail of ovary apex; D: flower bud, lateral view; E: petal; F: stamen, lateral view; G: hypanthium, lateral view; H: longitudinal section of flower with petals and stamens removed. – A–H from M. Ríos & al. 3316. – Drawing by Leticia Lajo (E).
Fig. 11.
Meriania escalerensis – A: terminal fertile branch with inflorescence; B: flower at anthesis, apical view. – A–B from M. Ríos & al. 3316. – Photographs by Luis Torres.
Phenology — Flowering occurs in September.
Distribution and ecology — Meriania escalerensis is probably endemic to elfin forests on high-elevation summits of the Cordillera Escalera (Loreto-San Martín border), on a sandstone substrate above 1950 m. The Cordillera Escalera is one of the “sub-Andean cordilleras” (Andean Tepuis sensu Neill & al. 2014) to the east of the E Andes. Common tree and shrub genera in the area include Clusia L. (Clusiaceae), Weinmannia L. (Cunoniaceae), Ocotea Aubl. and Persea Mill. (Lauraceae), Cybianthus Mart. (Primulaceae) and Palicourea Aubl. and Psychotria L. (Rubiaceae) (Neill & al. 2014).
Conservation status — Meriania escalerensis is known from a single collection from the Cordillera Escalera. Currently, the main threats facing the Cordillera Escalera are the lack of a legal designation to protect it, the Moyobamba-Balsapuerto highway project and gas and petroleum exploration and production (for more details see Pitman & al. 2014). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 4 km2, we recommend the category Critically Endangered CR B2ab(ii) for this species.
Etymology — The specific epithet refers to the type locality “Cordillera Escalera”.
Discussion — Meriania escalerensis may be related to the Meriania “brachycera” group (Mendoza-Cifuentes & Fernández-Alonso 2012), based on the presence of ferruginous indumentum, calyptrate calyx with circumscissile dehiscence, spreading corollas, and stamen connectives with ascending dorsal appendages. Within this group the species that are most similar to M. escalerensis are M. haemantha (Planch. & Linden) Humberto Mend. & Fern. Alonso (Colombia and Venezuela), M. sararensis Humberto Mend. & Fern. Alonso (Colombia) and M. yalconensis Humberto Mend. & Fern. Alonso (Colombia). However, M. escalerensis differs from the first by its leaf blades 13.3–15.5 × 7.6–8.8 cm (vs 11–31 × 6.5–22 cm), 5-merous flowers [vs 6–7(–9)-merous] and calyces 8–9.5 mm long (vs 9–19 mm); it differs from the second by its petioles 1.2–2.2 cm long (vs 2.7–3.8 cm), erect inflorescences (vs pendulous) and hypanthia and calyces with similar trichomes, up to 0.3 mm (vs clearly longer trichomes on the calyces, up to 1 mm); and it differs from the third by its 30–41 tertiary veins (vs 50–65), 5-merous flowers (vs 7- or 8-merous) and petals c. 21 mm long (vs 29–42 mm).
The only Peruvian species with calyptrate calyces are Meriania acida and M. tomentosa, the former endemic to N Peru and the latter distributed from Venezuela to Bolivia. Nevertheless, M. acida and M. tomentosa have calyces with irregular dehiscence and campanulate, reddish orange corollas, whereas M. escalerensis has calyces with circumscissile dehiscence and spreading, deep pink corollas. In addition, M. acida has leaf blades with acute bases and M. tomentosa with obtuse to rounded bases (vs cordate in M. escalerensis).
Currently, there are two species that grow in the sub-Andean Cordilleras of N Peru, Meriania escalerensis in the Cordillera Escalera (Loreto-San Martín border) and M. microflora Rob. Fern. & al. on the Cerros Kampankis (Amazonas-Loreto border). The two type localities are approximately 220 km apart and are dominated by oligotrophic sandstone substrates (Pitman & al. 2012; Pitman & al. 2014). Although M. escalerensis and M. microflora grow in similar habitats, they are quite different. The two species are easily distinguished by the petiole projections (absent in M. escalerensis vs present in M. microflora), the length and colour of the petals (c. 21 mm and deep pink vs 4–4.5 mm and white) and the shape of the stamens (isomorphic vs strongly dimorphic).
5. Meriania hirsuta Rob. Fern., Paredes-Burneo & Michelang., sp. nov. – Fig. 6, 12.
Holotype: Peru, Piura, Prov. Huancabamba, Dist. El Carmen de la Frontera, Río Samaniego margen izquierda, Zona de Amortiguamiento del Santuario Nacional Tabaconas-Namballe, 05°06′43.1″S, 79°21′25.7″W, 2150 m, 28 Apr 2003 (fl.), S. Baldeón & J. Campos 5373 (USM accession no. 273379!).
Diagnosis — A species differing from other congeners by the combination of branches and leaves with hirsute indumentum (elongate fluted trichomes up to 4 mm long), campanulate, deep red corollas, slightly dimorphic stamens, stamen connectives with one dorsobasal appendage that is almost perpendicular to the thecae and antisepalous stamen connectives with laterally expanded dorsobasal appendages.
Morphological description — Shrub up to 1.5 m tall; young branches and petioles hirsute with elongate fluted trichomes, these up to 4 mm long, moderately to densely on young branches, densely on petioles. Young branches terete or quadrangular, 5–7 mm in diam., lacking wings, nodes without interpetiolar flaps. Leaves opposite, isophyllous. Petioles terete, 5–15 mm long, without projections. Leaf blades subcoriaceous, 3.2–7.8 × 3–6.7 cm, ovate, apex acute, base cordate, margin denticulate, slightly discolorous; venation acrodromous and basal, with three pairs of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 14–16 on each side of primary, percurrent, 2–8 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation visible on adaxial surface, midvein, secondary and tertiary veins prominent and reticulation impressed on abaxial surface; adaxial surface bullate, black when dry, densely hirsute with trichomes similar to ones on petioles; abaxial surface dark brown when dry, moderately hirsute with trichomes similar to ones on petioles, denser on veins. Inflorescences not clear (see discussion). Flowers 5-merous, apparently pendant, with campanulate corollas; on swollen nodes 3–3.5 mm long, moderately hirsute with trichomes similar to ones on petioles. Pedicels 15–18 mm long, colour unknown, glabrous. Hypanthium 4–4.5 × 7–7.5 mm, campanulate, colour unknown, glabrous; torus glabrous. Calyx opening regularly, colour unknown, glabrous; tube 1.5 mm long; lobes repand; with 5 slightly callose dorsal projections, whitish and much lighter than rest of calyx and hypanthium when dry. Petals 12.5–13 × 11.5–12 mm, 4–4.5 mm wide at base, slightly obovate, apex rounded, margin entire, deep red, glabrous. Stamens 10, slightly dimorphic, all bent to one side of flower giving flower a zygomorphic appearance; antipetalous stamens filaments c. 8.5 mm long, colour unknown, flat, glabrous, connectives prolonged below thecae c. 0.3 mm long (not including perpendicular appendage), colour unknown, with one almost perpendicular dorsobasal appendage to thecae, c. 3 mm long, acute and with a rounded projection, c. 0.5 mm long, with an irregular surface, colour unknown, 1 mm from tip of dorsobasal appendage, anthers c. 6.5 mm long, lanceolate, colour unknown, glabrous, straight or with its apex slightly reflexed, opening by one slightly dorsally inclined pore, thecae surface smooth; antisepalous stamens with shape and size similar to antipetalous stamens, only difference being connectives with laterally expanded perpendicular dorsobasal appendages. Ovary 5-locular, superior, c. 4 × 4.5 mm, spheroidal and 5-lobed, colour unknown, c. 0.25 mm exceeding hypanthium length, glabrous; style 12–13 mm long, colour unknown, glabrous, slightly incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 1 mm wide, colour unknown. Fruits and seeds not seen.
Phenology — Flowering occurs in April.
Distribution and ecology — Meriania hirsuta is known only from two localities, about 5 km away from each other, between 2150 and 3035 m. This plant inhabits the montane forests of the E slopes of the Andes, at the northernmost limit of the Yungas (Comunidad Andina 2009), in the headwaters of the Samaniego river, which is part of the Chinchipe river basin. So far, this is a species endemic to Peru, found only in the Piura department (even though the paratype label records it for the Ayabaca province, it rather belongs to the Huancabamba province). Also, this species occurs in the core of the Amotape-Huancabamba zone, which is home of many other endemic species of Melastomataceae (Bussmann & Paniagua 2012; Bussmann & Paniagua 2013; Burke & al. 2017; Paredes-Burneo & al. 2018; Michelangeli & Paredes-Burneo 2019; Fernandez-Hilario & al. 2021a).
Fig. 12.
Meriania hirsuta – A: terminal fertile branches with inflorescences; B: detail of hirsute internode; C: detail of adaxial leaf surface; D: flower bud, lateral view; E: antisepalous stamen, lateral view, with detail of perpendicular dorsobasal appendage; F: antipetalous stamen, lateral view, with detail of perpendicular dorsobasal appendage; G: longitudinal section of flower with petals and stamens removed. – A–G from S. Baldeón & J. Campos 5373. – Drawing by Leticia Lajo (E, F).
Conservation status — The short range of occurrence of Meriania hirsuta is under the constant pressure of cattle grazing and logging, which might be prevented due to the recent setup of a Private Conservation Area (MINAM 2016). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 8 km2, we recommend the category Critically Endangered CR B2ab(iii) for this species.
Etymology — The specific epithet refers to the indumentum of this species.
Discussion — Meriania hirsuta is clearly distinguished from other species within the genus by its hirsute indumentum (trichomes up to 4 mm long) on the branches and leaves. Other species with similar indumentum are M. arizae Humberto Mend. & Fern. Alonso (trichomes up to 4.5 mm long), M. horrida C. Ulloa & Achá (up to 12 mm long) and M. mutisii (Humb. & Bonpl.) Humberto Mend. & Fern. Alonso (up to 4.5 mm long). However, M. arizae and M. mutisii belong to the Meriania “brachycera” group (Mendoza-Cifuentes & Fernández-Alonso 2012) characterized by its calyptrate calyces with circumscissile dehiscence and spreading corollas, whereas M. hirsuta has calyces with repand lobes and regular dehiscence and campanulate corollas. On the other hand, M. horrida has dendritic trichomes intermixed with simple trichomes (vs only simple in M. hirsuta), flowers 6(–7)-merous (vs 5-merous) with spreading, reddish purple corollas (vs campanulate, deep red).
Due to the characteristics of the leaves (bullate, ovate and cordate leaf blades) and flowers (campanulate, deep red corollas and stamen connectives with perpendicular dorsobasal appendages to the thecae), Meriania hirsuta seems to be closely related with species of the M. radula complex, formed by M. almedae Wurdack, M. radula (Benth.) Triana, M. tetragona and M. sanguinea. These species have isomorphic stamens and glabrous, granulose-furfuraceous or setulose abaxial leaf blades with dendritic trichomes up to 1 mm long, whereas M. hirsuta has hirsute indumentum with elongate fluted trichomes up to 4 mm long and slightly dimorphic stamens (antisepalous stamen connectives with laterally expanded appendages). Within M. radula complex, M. hirsuta and M. radula do not have interpetiolar flaps, but the former is distinguished from the latter by its abaxial leaf blades with trichomes only on nerves and reticulation (vs trichomes evenly covering the entire surface) and petals 12.5–13 mm long (vs 17–19 mm). The laterally expanded appendage of antisepalous stamen connective is a character observed in other Peruvian species such as M. amischophylla Wurdack, M. sumatika, M. vargasii Wurdack, M. vilcabambensis Wurdack and M. weberbaueri J. F. Macbr., but all these have stamen connectives with spreading, reddish purple corollas and stamen connectives with descending dorsobasal appendages (vs perpendicular dorsobasal in M. hirsuta) and ascending dorsal appendages of the antisepalous stamens (vs absent in M. hirsuta), except M. amischophylla, which has dorsal appendages as mere humps, and M. weberbaueri, which lacks dorsal appendages.
The location of the inflorescences on the branches in Meriania hirsuta is unclear as the only fertile specimen (Baldeón & Campos 5373) has three short branches with flowers located at the distal nodes. The inflorescences could be interpreted as axillary fascicles (8–10-flow-ered) or as one terminal panicles (8–18.5 cm long with 3 nodes). The former is a feature not seen within Meriania and the latter is present in all species within the M. radula complex, although in these species the inflorescences longer than 18 cm and with more than (4 or)5 nodes.
Additional specimens examined (paratypes) — Peru: Piura, Prov. Ayabaca [Huancabamba], Dist. El Carmen de la Frontera, Carretera Sapalache-Cerro Chinguelas, 05°08′23.6″S, 79°23′45.4″W, 3035 m, 3 Sep 2016 (sterile), F. A. Michelangeli & al. 2636 (NY!, USM!).
6. Meriania juanjil Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 6, 13.
Holotype: Peru, Amazonas, Prov. Bongará, Montane rainforest along Yambrasbamba-Pomacocha trail between Yambrasbamba and Yanayacu, 2200–2300 m, 26 Jun 1962 (fl.), J. Wurdack 1054 (USM accession no. 27403!; isotypes: F accession no. 1601214!, NY barcode 02499960!, P barcode 05225706!, US barcode 02925052!).
Diagnosis — A species differing from other congeners by the combination of elliptic leaf blades (10.8–12.7 × 2.7–3 cm) with moderately puberulent indumentum on the abaxial surfaces, 3-nerved venation, subcalyptrate calyces with small conic dorsal projections (0.5 mm long) and irregular dehiscence, campanulate, pink-orange corollas and isomorphic stamens.
Morphological description — Shrub up to 5 m tall; young branches and petioles puberulent, glabrescent to sparsely so on young branches with stellulate trichomes up to 0.13 mm long, sparsely to moderately on petioles with stellate trichomes up to 0.13 mm long. Young branches quadrangular, 4–5.5 mm in diam., lacking wings, nodes without interpetiolar flaps and leaf axils moderately covered with elongate, slightly roughened trichomes up to 2 mm long. Leaves opposite, isophyllous. Petioles quadrangular, 1.8–2.3 cm long, without projections. Leaf blades coriaceous, 10.8–12.7 × 2.7–3 cm, elliptic, apex acute, base acute to slightly obtuse, margin entire, discolorous; venation acrodromous and suprabasal, with one pair of secondaries (lateral nerves), diverging 3–4.5 mm from base of blade and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 27–32 on each side of primary, percurrent, 1.5–5 mm distant from each other, midvein and secondary veins impressed, tertiary veins and reticulation barely to not visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent, reticulation impressed on abaxial surface; adaxial surface flat, dark olive when dry, glabrous; abaxial surface light olive when dry, midvein and secondary veins moderately puberulent with stellate trichomes up to 0.13 mm long intermixed with elongated slightly roughened trichomes up to 0.5 mm long, secondary veins and reticulation sparsely puberulent with only stellate trichomes, with elongated slightly roughened trichomes up to 1 mm long at convergence of midvein and secondary veins. Inflorescences pseudolateral panicles (initially terminal but overtopped by developing axillary bud), erect, 6.8–10 × 4.8–8.3 cm, submultiflorous or multiflorous; axis and peduncle moderately puberulent with stellate trichomes up to 0.13 intermixed with elongated trichomes with a substellate base up to 0.75 mm, longer (up to 1.5 mm long) on nodes. Peduncle 1.8–2.4 cm long, quadrangular. Main axis 5.2–5.9 cm, quadrangular, with 2(or 3) pairs of proximal paraclades and two nodes, subdistal node with 3 pairs of flowers, distal node with an umbel. Paraclades in proximal pairs, 3.8–4.5 cm long; flowers in 5–7-flowered umbels at ends of branchlets. Bracts foliaceous, persistent, 7–10.5 × 1.8–2.9 cm, petioles 1.6–3.4 cm long, shape and indumentum similar to principal leaves; sometimes with one pair of additional bracts on subproximal paraclades of main axis, 4.1–6.5 × 1–1.6 cm, petioles 1.8–2 cm long. Bracteoles not seen (probably early caducous). Flowers 5-merous, pendant, with campanulate corollas. Pedicels 6–8 mm long, colour unknown, moderately puberulent covered with trichomes similar to ones on peduncle and axis. Hypanthium c. 3.5 × 4 mm, campanulate, colour unknown, outer surface moderately puberulent covered by trichomes similar to ones on pedicels, inner surface glabrous; torus glabrous. Calyx opening irregularly, colour unknown, outer surface moderately puberulent with stellate trichomes up to 0.13 mm long, inner surface sparsely puberulent with similar trichomes; calyx lobes closely connate in bud, forming a subcalyptra, 3–3.5 mm long, each with a small conic dorsal projection, 0.5 mm long, at maturity splitting irregularly into 2–3 segments, segments irregularly acute to obtuse. Petals 11–13.5 × 10–12.5 mm, c. 2 mm wide at base, obovate and slightly asymmetric, apex rounded, margin entire, pink-orange, glabrous. Stamens 10, isomorphic, all bent to one side of flower giving flower a zygomorphic appearance; filaments 6.5–7 mm long, colour unknown, flat, glabrous; connectives prolonged below thecae c. 0.5 mm (not including descending dorsobasal appendage), colour unknown, glabrous, with one descending dorsobasal appendage, c. 0.75 mm long, acute; anthers 5.5–6 mm long, lanceolate, colour unknown, glabrous, straight or with apices slightly reflexed, opening by one apical to slightly dorsally inclined pore, thecae surfaces smooth. Ovary 5-locular, superior, free, c. 3 × 2.5 mm, oblong and slightly 5-lobed, colour unknown, not exceeding hypanthium length, glabrous; style c. 22.5 mm long, colour unknown, glabrous, slightly incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.8 mm wide, colour unknown. Fruits and seeds not seen.
Fig. 13.
Meriania juanjil. Terminal fertile branch with inflorescences; B: detail of convergence of midvein and secondary veins, abaxial view; C: detail of calyx apex; D: inflorescence branch; E: stamen, lateral view; F: petal; G: flower with petals and stamens removed. – A–G from J. Wurdack 1054.
Phenology — Flowering occurs in June.
Distribution and ecology — Meriania juanjil is endemic to high-elevation montane forests in Bongará province in the Department of Amazonas, on moderately sloping terrain at 2200–2300 m.
Conservation status — Meriania juanjil is known from a single collection from Bongará province. Currently, the pristine forests in the Bongará province are decreasing due to the expansion of agriculture and livestock (see additional comments under M. bongarana). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 4 km2, we recommend the category Critically Endangered CR B2ab(iii) for this species.
Etymology — The specific epithet “juanjil” refers to the name applied by local people in Bongará to the Melastomataceae. Because the epithet is a noun in apposition, it retains its own termination irrespective of the gender of the generic name (see Turland & al. 2018: Art. 23.5).
Discussion — Meriania juanjil is clearly distinguished from other species within the genus by the combination of subcalyptrate calyces with small conic dorsal projections (c. 0.5 mm long) and irregular dehiscence, campanulate, pink-orange corollas and isomorphic stamens. The calyx lobes are closely connate in bud, forming a subcalyptra or calyptra, a feature present in other genera within Merianieae (such as Centronia and Graffenrieda) and outside the tribe (e.g. Alloneuron Pilg., Miconia Ruiz & Pav., Mouriri Aubl., Wurdastom B. Walln.). Meriania species with these characteristics can be separated into two artificial groups, the first one with species with spreading corollas (e.g. M. brachycera (Naudin) Humberto Mend. & Fern. Alonso, M. escalerensis, M. kirkbridei Wurdack, M. maguirei Wurdack) and the second one with campanulate corollas (e.g. M. acida, M. grandiflora (Standl.) Almeda, M. phlomoides (Triana) Almeda, M. tomentosa, M. vasquezii). Within the latter group, M. juanjil is similar to M. denticulata (Ecuador) and M. vasquezii, also described here from Peru (see comments under the latter for differences). These three species share the subcalyptrate calyx with small dorsal projections and irregular dehiscence. However, M. juanjil is distinguished from M. denticulata by its leaf blades 10.8–12.7 × 2.7–3 cm [vs 9–21(–24) × 5–12(–17) cm] and 3-nerved [vs 5(–7)-nerved] and petals 11–13.5 × 10–12.5 mm (vs 8–10 × 7–8 mm).
In Peru, there are three other species of Meriania with a calyptrate calyx [M. acida, M. escalerensis (also described here) and M. tomentosa], but none of them has dorsal projections on the calyx. Meriania escalerensis differs from the other species by its calyces with circumscissile dehiscence (vs irregular dehiscence) and spreading, reddish purple corollas (vs campanulate, pink-orange to reddish orange corollas). Additionally, M. juanjil is distinguished from M. acida and M. tomentosa by its subcalyptrate calyx (vs calyptrate) and also differs from the former by its leaf blades 2.7–3 cm wide (vs 5–8 cm wide) and petals 11–13.5 mm long (vs 9–10 mm long). Meriania juanjil differs from the latter by its abaxial leaf surface with trichomes only on the nerves (vs evenly covering the entire surface) and inflorescences 6.8–10 cm long (vs 19.9–32.3 cm long).
7. Meriania megaphylla Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 6, 14.
Holotype: Peru, La Libertad, Prov. Pataz, Dist. Ongón, valle del río Mixiollo, 2000–2100 m, 4 Aug 1914 (fl.), A. Weberbauer 7048 (MOL barcode 00003237!; isotypes: F-fragment accession no. 628681!, MOL-fragment barcode 00003236!).
Diagnosis — A species differing from other congeners by the combination of 4-winged and quadrangular branches, interpetiolar flaps (5–8 mm long), large leaf blades (21–29.4 × 14.8–22 cm), spreading, reddish purple corollas, isomorphic stamens, and stamen connectives with two appendages, one a triangular descending dorsobasal appendage and the other a blunt ascending dorsal appendage.
Morphological description — Scandent shrub; young branches and petioles glabrous. Young branches quadrangular, 4-winged, 5–11 mm in diam., nodes with interpetiolar flaps, 5–8 mm long. Leaves opposite, slightly anisophyllous. Petioles quadrangular, 7.6–11.6 cm long, with an adaxial projection (scutum) at insertion of petiole with leaf blade, up to 1 mm tall, obscured by trichomes. Leaf blades coriaceous, 21–29.4 × 14.8–22 cm, ovate, apex broadly obtuse, base cordate, margin finely serrulate, concolorous; venation acrodromous and basal, with three pairs of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 38–40 on each side of primary, percurrent, 2–10 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation visible on adaxial surface, midvein and secondary veins salient, tertiary veins and reticulation prominent on abaxial surface; adaxial surface bullate; both surfaces light olive when dry, glabrous. Inflorescences terminal panicles, erect, c. 25.9 × 10 cm, multiflorous; axis and peduncle glabrous. Peduncle c. 8.9 cm long, quadrangular, 4-winged. Main axis c. 15.6 cm long, quadrangular, 4-winged. Paraclades in 5 pairs, proximal c. 8.8 cm long, distal c. 2.2 cm long; flowers in 5-flowered umbels at ends of branchlets. Bracts foliaceous, persistent, 3.7–6 × 1.5–1.8 cm, petioles 8–13 mm long, elliptic, indumentum similar to ones on leaves. Bracteoles not seen (probably early caducous). Flowers 5–merous, with spreading corollas. Pedicels 6–8 mm long, colour unknown, glabrous to sparsely puberulent with short trichomes, up to 0.10. Hypanthium 4.5–5 × 4–4.5 mm, campanulate, colour unknown, outer and inner surface glabrous to sparsely puberulent with trichomes similar to ones on pedicels; torus glabrous. Calyx opening regularly, colour unknown, outer and inner surface glabrous to sparsely puberulent with trichomes similar to ones on pedicels; tube 1.5–2 mm long; lobes repand; with 5 blunt dorsal projections, c. 0.5 mm long. Petals 20.5–22.5 × 19–21 mm, 2.5–3 mm wide at base, strongly asymmetrically obovate, apex asymmetric, margin entire, reddish purple, glabrous. Stamens 10, isomorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; filaments 10.5–11 mm long, colour unknown, flat, glabrous; connectives not prolonged below thecae, colour unknown, glabrous, with two appendages, one descending dorsobasal, 4–4.5 mm long, triangular, other ascending dorsal appendage, c. 0.75 mm long, blunt and c. 4.5 mm from tip of descending dorsobasal appendage; anthers 8–8.5 mm long, lanceolate, colour unknown, glabrous, straight, opening by one dorsally inclined pore, thecae surface corrugated. Ovary 5–locular, superior, c. 4.5 × 3 mm, oblong, colour unknown, not exceeding hypanthium length, glabrous; style 11.5–13.5 mm long, colour unknown, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.5 mm wide, colour unknown. Fruits and seeds not seen.
Phenology — Flowering occurs in August.
Distribution and ecology — Meriania megaphylla is endemic to high-elevation montane forests in the Pataz province (Department of La Libertad), between 2000 and 2100 m. The vegetation of this region is part of the relict montane forests from the W slopes of the Andes in NW Peru (see Weigend & al. 2005).
Conservation status — Meriania megaphylla is known from a single collection made in 1914. Increased deforestation in recent years and artisanal mining threaten the montane forests of Pataz. However, because these crucial forests are at present virtually unknown, we propose that at this time M. megaphylla be considered as Data Deficient DD (IUCN 2012, 2019).
Etymology — The specific epithet refers to the unusually large leaves of this species.
Fig. 14.
Meriania megaphylla – A: terminal fertile branch with inflorescence; B: detail of interpetiolar flap; C: detail of leaf base; D: flower at anthesis, apical view; E: stamen, lateral view; F: petal; G: flower with petals and stamens removed. – A–G from A. Weberbauer 7048.
Discussion — Meriania megaphylla is distinguished from other species within the genus by the combination of quadrangular and 4-winged internodes, nodes with interpetiolar flaps, an adaxial projection (scutum) at the insertion of the petiole with the leaf blade and large leaf blades (21–29.4 × 14.8–22 cm). Quadrangular and winged internodes also occur in M. tetragona (Ecuador and Peru), M. penningtonii (Peru) and M. nobilis Triana (Colombia), but only M. penningtonii lacks interpetiolar flaps on the nodes (vs present in the other species). Additionally, M. nobilis has leaf blades with flat adaxial surfaces (vs bullate in M. megaphylla), revolute margins at the base (vs entire) and dimorphic stamens (vs isomorphic). In addition, M. megaphylla differs from M. tetragona by its petioles with adaxial projections (vs abaxial projections), leaf blades 21–29.4 × 14.8–22 cm (vs 7–12 × 3–9 cm) and spreading, reddish purple corollas (vs campanulate, deep red).
Due to the large bullate leaf blades and spreading, reddish purple corollas, the type specimen of Meriania megaphylla (Weberbauer 7048) had been erroneously identified as M. tetraquetra Triana, a poorly known species endemic to N Peru (Department of Amazonas). However, M. tetraquetra probably belongs in a group of species that includes M. penningtonii and M. rugosa Markgr., these also endemic to N Peru. These species are trees with bullate leaves, spreading corollas, reddish purple petals, isomorphic stamens, and stamen connectives with two appendages, one a triangular descending dorsobasal appendage and the other dorsal appendage a mere hump or absent. Within this group M. megaphylla differs from M. penningtonii by its petioles with adaxial projections (vs absent), calyces with blunt dorsal projections (vs callose) and stamens connectives with blunt ascending appendages (vs mere humps). Also, M. megaphylla can be distinguished from M. tetraquetra and M. rugosa by its quadrate and 4-winged internodes (vs quadrate but not winged in M. tetraquetra and M. rugosa), ovate, 21–29.4 × 14.8–22 cm leaf blades (vs oblong, 27–35 × 13–20 cm in M. tetraquetra and elliptic, 15–17 × 7–8 cm in M. rugosa), calyx with blunt dorsal projections, c. 0.5 mm long (vs absent in M. tetraquetra and blunt, 2–3 mm long in M. rugosa) and stamen connectives with ascending blunt dorsal appendages (vs absent in M. tetraquetra and M. rugosa).
Meriania is traditionally characterized by its arboreal or shrubby habit with the exception of M. selvaflorensis Humberto Mend. (Colombia) which has a lianescent habit. The lianescent habit is also present in other genera within of the Merianieae (Adelobotrys and Graffenrieda). However, according to the label information on Weberbauer 7048, M. megaphylla has a scandent habit. Meriania megaphylla is easily distinguishable from M. selvaflorensis by its quadrangular and 4-winged branches (vs terete), developed interpetiolar flaps (vs absent), bullate leaf blades (vs flat) and lobed calyx (vs calyptrate).
8. Meriania sumatika Rob. Fern., R. Goldenb. & Michelang., sp. nov. – Fig. 15–16.
Holotype: Peru, Cusco, Prov. Urubamba, Dist. Machupichu, Santuario Histórico de Machupicchu y en Camino Inca, 13°09′10″S, 72°31′00″W, 2060 m, 14–22 Oct 1987 (fl., fr.), P. Nuñez & J. Arque 8369 (CUZ accession no. 15097!; isotypes: F accession no. 2028864!, US barcode 02925646!).
Diagnosis — A species differing from other congeners by the combination of 10-costate hypanthia (ridges up to 4.5 mm high in fruit), spreading, reddish purple corollas, large petals (46–55 mm long), dimorphic stamens, stamen connectives with two appendages, one a descending dorsobasal appendage and the other a blunt ascending dorsal appendage, and antisepalous stamen connectives with laterally expanded dorsobasal appendages.
Morphological description — Tree up to 20 m tall; young branches and petioles tomentose with elongated trichomes with greatly roughened base, these up to 1 mm long, sparsely to densely on young branches, densely on petioles. Young branches quadrangular, 2.5–4.5 mm in diam., nodes without interpetiolar flaps. Leaves opposite, isophyllous, rarely anisophyllous. Petioles quadrangular, 1.1–4.8 cm long, without projections. Leaf blades coriaceous, 10–17 × 3.7–8.8 cm, elliptic to ovate, apex acute, base acute to obtuse, margin finely serrulate on distal half to two-thirds, discolorous; venation acrodromous and suprabasal, with one two of secondaries (lateral nerves), first pair diverging 2–3 mm from base of blade, second pair diverging 5–10 mm from base of blade and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 30–40 on each side of primary, percurrent, 2–10 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation visible or barely visible on abaxial surface; adaxial surface flat, olive-green when dry, glabrous or with sparse elongated trichomes with greatly roughened base, denser near base of midvein, up to 1 mm long; abaxial surface greenish ferruginous to ferruginous when dry, densely tomentose to villose with elongated trichomes with greatly roughened base up to 1.5 mm long, similar to ones on petioles, covering almost entire surface. Inflorescences terminal panicles, erect, 10–22.5 × 12–23 cm, few-flowered; axis and peduncle densely tomentose with trichomes similar to ones on twigs and petioles, up to 1.5 mm long. Peduncle 2–5.5 cm long, quadrangular. Main axis 3.1–10.4 cm long, quadrangular, with 1–2 pairs of proximal paraclades and two nodes, subdistal node with 2 flowers, distal node with a dichasium. Paraclades in ones proximal pairs, 5.5–11.7 cm long; flowers in regular dichasia at ends of branchlets. Bracts foliaceous, persistent, 9.9–11.5 × 2.8–6.6 cm, petioles 1.1–3.7 cm long, shape and indumentum similar to principal leaves; sometimes with one pair of additional bracts on proximal nodes of main axis, c. 6 × 1.6 cm, petioles 1 cm long. Bracteoles (in Huamantupa & al. 2060) caducous, 17–20 mm long, lanceolate, indumentum similar to ones on bracts. Flowers 5–merous, with spreading corollas. Pedicels c. 6 mm long, ferruginous, densely tomentose, trichomes up to 1 mm long, similar to ones on inflorescence axis. Hypanthium c. 9.5 × 10.5–11 mm, campanulate, 10-costate, ridges irregular and obscured by trichomes, up to 2–5 mm high, ferruginous, outer surface densely tomentose to villose with trichomes similar to ones on pedicels, up to 1.5 mm long, inner surface glabrous; torus glabrous. Calyx opening regularly, ferruginous, outer surface densely tomentose to villose with trichomes similar to ones on hypanthia, up to 1.5 mm long, inner surface moderately tomentose with same trichomes, up to 1 mm long; tube 2.5–3.5 mm long; lobes 14.5–15 × 8–9 mm, acute, each with a falcate dorsal projection, 14.5–15.5 mm long. Petals 46–55 × 38 mm, 4–5 mm wide at base, obovate and slightly asymmetric, apex rounded, margin entire, purple, glabrous. Stamens 10, dimorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; antisepalous stamens filaments 28–29 mm long, purple, flat, glabrous, connectives not prolonged below thecae, dark purple in thecae, white in transition to descending dorsobasal appendage, with very short and irregular projections on dorsal surface from tip of descending dorsobasal appendage to base of ascending dorsal appendage, with two appendages, one descending dorsobasal, laterally expanded, 7–8 mm long, acute and crowned, yellow, other ascending dorsal appendage c. 1 mm long, blunt, purple, 4.5–5 mm from tip of descending dorsobasal appendage, anthers 14–15 mm long, lanceolate, dark purple, glabrous, with its apical third slightly reflexed, opening by one dorsally inclined pore, thecae surface corrugated; antipetalous stamens filaments 24–25 mm long, purple, flat, glabrous, connectives not prolonged below thecae, dark purple in thecae, white in transition to descending dorsobasal appendage, with very short and irregular projections from tip of descending dorsobasal appendage to base of ascending dorsal appendage, denser on dorsal surface, with two appendages, one descending dorsobasal, 12–13 mm long, acute, yellow, other ascending dorsal appendage, c. 1 mm long, blunt, purple, 7–7.5 mm from tip of descending dorsobasal appendage, anthers 15.5–16 mm long, lanceolate, dark purple, glabrous, straight, opening by one dorsally inclined pore, thecae surface corrugated. Ovary 5–loc-ular, superior, free, c. 6.5 × 4 mm, oblong, colour unknown, not exceeding hypanthium length, glabrous; style c. 15 mm long, reddish purple, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 0.75 mm wide, colour unknown. Fruits capsular (velatidia), with a persistent hypanthium, clearly 10-costate, ridges up to 4.5 mm high, calyx caducous; mature ovary c. 11 × 10–10.5 mm, spheroid, slightly costate, completely concealed by hypanthium; fruiting pedicels 8–11 mm long. Seeds triangular-linear, 1–1.5 mm long, numerous.
Fig. 15.
Meriania sumatika – A: terminal fertile branch with inflorescence; B: infructescence branch; C: flower at anthesis, apical view; D: petal; E: antisepalous stamen, lateral view; F: antipetalous stamen, lateral view; G: longitudinal section of flower with petals and stamens removed. – A from W. Galiano & al. 6410; B–G from P. Nuñez & J. Arque 8369. – Drawing by Leticia Lajo.
Phenology — Flowering occurs in February, May and October and fruiting in May and October.
Distribution and ecology — Meriania sumatika is endemic to high-elevation montane forests within the Machu Picchu National Sanctuary (Urubamba province) and in the Santa Ana district (La Convención province) in the Department of Cusco, between 1800 and 2900 m. Individuals of this new species have been previously recorded by Alfaro & al. (2018), as M. tomentosa, in “Wiñaywayna” and growing with Aniba coto (Rusby) Kosterm. (Lauraceae), Gordonia fruticosa (Schrad.) H. Keng (Theaceae), Hieronyma oblonga (Tul.) Müll. Arg. (Phyllanthaceae), Meliosma peytonii A. H. Gentry (Sabiaceae) and Myrcia fallax (Rich.) DC. (Myrtaceae).
Conservation status — All Meriania sumatika specimens were collected in the Machu Picchu National Sanctuary (except Huamantupa & al. 2060). Within this sanctuary, the main threat are forest fires for the establishment of crops (CENEPRED 2020). Therefore, following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 24 km2, we recommend the category Endangered EN B2ab(iii) for this species.
Etymology — The specific epithet comes from the Quechua “sumaq” (= beautiful) and “tika” (= flower), referring to large showy flowers of this species. Because “tika” is a noun in apposition, the epithet retains its own termination irrespective of the gender of the generic name (see Turland & al. 2018: Art. 23.5).
Discussion — Meriania sumatika is distinguished from other species within the genus by the combination of 10-costate hypanthium, spreading, reddish purple corolla and large petals (46–55 mm long). In the Andean region only two other species have costate hypanthia, M. campii Wurdack and M. costata Wurdack, both species endemic to Ecuador. Meriania sumatika is distinguished from M. campii by the leaf blades 10–17 × 3.7–8.8 cm (vs 6–12 × 4–8 cm in M. campii), calyx lobes with falcate dorsal projections, 14.5–15.5 mm long (vs blunt carnose, 1.7–4 mm) and dimorphic stamens (vs isomorphic). Meriania sumatika also shares falcate dorsal projections on the calyx lobes with M. costata. Nevertheless, M. sumatika differs from M. costata by its spreading, reddish purple corollas (vs campanulate, reddish orange), petals 46–55 mm long (vs c. 22 mm) and stamen connectives not prolonged below the thecae (vs 1.5–1.7 mm prolonged).
Among Peruvian species of Meriania, M. sumatika probably belongs in a group of species that includes M. amischophylla, M. vargasii Wurdack and M. weberbaueri J. F. Macbr.; the first and third species are endemic to central Peru and the second one is endemic to S Peru. These species are trees with tomentose to villose indumentum, calyx lobes with dorsal projections, spreading corollas, deep pink to reddish purple petals, dimorphic stamens and antisepalous stamen connectives with laterally expanded descending dorsobasal appendages. Within this group M. sumatika can be distinguished by its 10-costate hypanthium (vs terete in the other species), calyx lobes with falcate dorsal projections, 14.5–15.5 mm long (vs acute, 1–1.5 mm in M. amischophylla; falcate, 5–6 mm in M. vargasii; and acute, up to 3 mm in M. weberbaueri) and petals 46–55 mm long (vs 19–32 mm in M. amischophylla; 20–24 mm in M. vargasii; and 20–25 mm in M. weberbaueri).
Almost all Meriania sumatika specimens were previously determined as M. tomentosa. In fact, the two species are almost indistinguishable based on vegetative characters. Meriania sumatika differs from M. tomentosa by its 10-costate hypanthium (vs terete in M. tomentosa), lobed calyx with regular dehiscence (vs calyptrate with irregular dehiscence) and spreading, reddish purple corollas (vs campanulate, reddish orange).
Here we place Huamantupa & al. 2060 (in flower bud) in Meriania sumatika with reservation, because it has slightly costate hypanthia and calyx lobes with smaller dorsal projections (4–5 mm vs 14.5–15.5 mm). In addition, this specimen was collected 41 km away from the others.
Additional specimens examined (paratypes) — Peru: Cusco, Prov. Urubamba, Dist. Machupichu, Intipata, Santuario Histórico de Machu Picchu, 2950 m, 10 Feb 1990 (fl.), A. Cano & al. 2874 (HUT!); Wiñay-Wayna, Machupichu, 2850–2900 m, 21 May 1991 (fr.), H. Dueñas 27 (CUZ!); Microcuenca Wiñaywayna, Wiñaywayna-Intipunku, 13°10′23.04″S, 72°32′03.44″W, 2700 m, 24 Jun 2001 (fr.), R. Tupayachi & al. 4926 (CUZ!); camino Inca, entre Wiñay Wayna e Intipunku, quebrada Wacraytambo, 13°10′42″S, 72°32′02″W, 2737 m, 24 May 2004 (fl., fr.), W. Galiano & al. 6410 (CUZ!, NY!); Prov. La Convención, Dist. Santa Ana, Potrero, 13°53′56″S, 72°43′50″W, 1800 m, 27 May 2002 (fl. bud), I. Huamantupa & al. 2060 (USM!).
9. Meriania vasquezii Rob. Fern., R. Villanueva & Michelang., sp. nov. – Fig. 3, 17, 18.
Holotype: Peru, Pasco, Prov. Oxapampa, Dist. Chontabamba, Ulcumano Lodge, 10°38′08″S, 75°25′39″W, 2244 m, 23 Feb 2021 (fl.), R. Vásquez, L. Valenzuela, E. Pinche & C. Rojas 45480 (HOXA accession no. 077441!; isotypes: MO!, MOL barcode 000009!, UPCB accession no. 99426!).
Diagnosis — A species differing from other congeners by the combination of leaf blades with dense villose indumentum on the abaxial surfaces, inflorescences with flowers in regular dichasia at the ends of branchlets, subcalyptrate calyx with small dorsal projections (c. 3 mm long) and irregular dehiscence, campanulate, deep pink corollas, dimorphic stamens and antisepalous stamen connectives with laterally expanded descending dorsobasal appendages.
Fig. 17.
Meriania vasquezii – A: terminal fertile branch with inflorescence and detail of inflorescence branch; B: detail of abaxial leaf surface; C: detail of calyx apex; D: antisepalous stamen, lateral view, with detail of descending dorsobasal appendage; E: antipetalous stamen, lateral view, with detail of descending dorsobasal appendage; F: hypanthium and calyx after anthesis. – A–F from R. Vásquez & al. 45480.
Fig. 18.
Meriania vasquezii – A: terminal fertile branch with inflorescence; B: detail of inflorescence; C: flower at anthesis, apical view; D: immature fruit. – A–D from R. Vásquez & al. 45480. – Photographs by Rodolfo Vásquez.
Morphological description — Shrub up to 2.5 m tall; young branches and petioles pubescent with stellate trichomes up to 0.25 mm long, sparsely to moderately on young branches, moderately to densely on petioles. Young branches quadrangular, 5–5.5 mm in diam., lacking wings, nodes without interpetiolar flaps. Leaves opposite, isophyllous. Petioles quadrangular, 2.2–5 cm long, without projections. Leaf blades coriaceous, 16.5–23.5 × 9.3–10.7 cm, broadly elliptic to ovate, apex acuminate, base rounded to obtuse, margin denticulate on distal half and entire to obscurely denticulate on proximal half, discolorous; venation acrodromous and suprabasal, with one or two pairs of secondaries (lateral nerves), diverging 3–7 mm from base of blade and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 40–44 on each side of primary, percurrent, 2–9 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins and reticulation prominent on abaxial surface; adaxial surface slightly bullate, dark when dry, glabrous or with sparse elongated trichomes with a substellate base, denser near base, up to 1.5 mm long; abaxial surface golden brown when dry, midvein, secondary veins, tertiary veins, reticulation and surface densely villose with elongated curly trichomes with a substellate base up to 2.5 mm long, evenly covering entire surface. Inflorescences terminal panicles, erect, 26.5–29.5 × 12.3–14 cm, submultiflorous; axis and peduncle densely tomentose with elongated trichomes with a substellate base up to 1 mm long, longer (up to 2.5 mm long) on nodes. Peduncle c. 7.5 cm long, quadrangular. Main axis 18.1–18.3 cm, quadrangular. Paraclades in 4 pairs, proximal 10.5–14.7 cm long, distal 3.9–4 cm long; flowers in regular dichasia at ends of branchlets. Bracts foliaceous, persistent, 16.5–19.1 × 9.3–10.5 cm, petioles 2.2–3.4 cm long, shape and indumentum similar to principal leaves. Bracteoles caducous, c. 20 × 1 mm, linear, indumentum similar to ones on peduncle and axis. Flowers 5-mer-ous erect, with campanulate corollas. Pedicels 9–12 mm long, golden brown, densely tomentose to villose covered with trichomes similar to ones on peduncle and axis. Hypanthium c. 11 × 7 mm, campanulate, sometimes slightly costate, ridges obscured by trichomes, up to 0.75 mm high, golden brown, outer surface densely tomentose to villose covered by trichomes similar to ones on pedicels, inner surface glabrous; torus glabrous. Calyx opening irregularly, golden brown, outer surface densely tomentose to villose covered by trichomes similar to ones on pedicels, inner surface glabrous; calyx lobes closely connate in bud, forming a subcalyptra, 7.5–8.5 mm long, each with a small claw-shaped dorsal projection, c. 3 mm long, at maturity splitting irregularly. Petals 25–31 × 23–26 mm, c. 4 mm wide at base, obovate and slightly asymmetric, apex rounded, margin entire, deep pink, glabrous. Stamens 10, dimorphic, all bent to one side of flower giving flower a zygomorphic appearance; antisepalous stamens with filaments 12–13.5 mm long, light purple, glabrous; connectives prolonged below thecae c. 1 mm (not including descending dorsobasal appendage), purple, glabrous, with two appendages, one descending dorsobasal, laterally expanded, 3–3.5 mm long, acute and slightly crowned, light purple, other appendage dorsal appendage a mere hump, c. 0.5 mm, broadly rounded, light purple, 1.5–2 mm from tip of descending dorsobasal appendage, anthers c. 11.5 mm long, lanceolate, purple, glabrous, straight or with its apical portion slightly reflexed, opening by one dorsally inclined pore, thecae surface corrugated; antipetalous stamens with filaments 12–13 mm long, light pink, glabrous; connectives prolonged below thecae 1–1.5 mm (not including descending dorsobasal appendage), purple, glabrous, with one descending dorsobasal appendage, 2.5–3 mm long, triangular, light purple, anthers c. 12 mm long, lanceolate, purple, glabrous, straight or with its apical portion slightly reflexed, opening by one dorsally inclined pore, thecae surface corrugated. Ovary 5-locular, superior, free, c. 6 × 4 mm, oblong and slightly 5-lobed, colour unknown, not exceeding hypanthium length, glabrous; style c. 20 mm long, purple, glabrous, slightly incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 1 mm wide, whitish. Fruits and seeds not seen.
Phenology — Flowering occurs in February.
Distribution and ecology — Meriania vasquezii is endemic to high-elevation montane forests in the Oxapampa province in the Department of Pasco, on moderate slopes at 2244 m.
Conservation status — Meriania vasquezii is known from a single collection from Oxapampa province. Increased fieldwork in montane and premontane forests in this region has led to the discovery of several new species of Melastomataceae in recent years (Cárdenas & al. 2014; Michelangeli & Goldenberg 2018, 2021). Therefore, the effective protection of the diverse habitats in Oxapampa province is a high priority. Following IUCN (2012, 2019) guidelines and based on an estimated area of occupancy of 4 km2, we recommend the category Critically Endangered CR B2ab(iii) for this species.
Etymology — It is an honour to dedicate this species to Rodolfo Vásquez, researcher at the Estación Biológica del Jardín Botánico de Missouri, who for over 30 years has made an incredible contribution to the knowledge of the flora of Peru. He wrote Flórula de las reservas biológicas de Iquitos, Perú (Vásquez 1997) and led the publication of Flora del Río Cenepa, Amazonas Perú (Vásquez & al. 2010a, 2010b).
Discussion — Meriania vasquezii is distinguished from other congeners by the combination of subcalyptrate calyces with small claw-shaped dorsal projections (c. 3 mm long) and irregular dehiscence, campanulate, deep pink corollas, dimorphic stamens and antisepalous stamen connectives with laterally expanded dorsobasal appendages. The species with calyptrate or subcalyptrate calyces and campanulate corollas usually have pink-orange to reddish orange petals (see additional comments under M. juanjil). However, M. vasquezii is the exception within this group by its deep pink petals. Also, the only Peruvian species with a subcalyptrate calyx and campanulate corolla is M. juanjil.
In Peru, the species of Meriania with calyx lobes closely connate in bud can be separated into two artificial groups; species with calyptrate calyces [M. acida, M. escalerensis (also described here) and M. tomentosa] and species with subcalyptrate calyces (M. juanjil and M. vasquezii). Nevertheless, M. vasquezii is easily distinguished within the former group by its small claw-shaped dorsal projections on the calyx (vs absent in the other species) and dimorphic stamens (vs isomorphic). Meriania vasquezii most closely resembles M. juanjil. They share subcalyptrate calyces with dorsal projections and campanulate corollas, but both species can be distinguished by the leaf blade size (16.5–23.5 × 9.3–10.7 cm in M. vasquezii vs 10.8–12.7 × 2.7–3 cm in M. juanjil), arrangement of flowers at branchlet ends (regular dichasia vs 5–7-flowered umbels) and length and colour of the petals (25–31 mm long and light purple vs 11–13.5 mm long and pink-orange).
New record
10. Meriania zunacensis D. Fernández & Dellinger in Phytotaxa 458: 7. 2020. – Holotype: Ecuador, Prov. Tungurahua, Cantón Baños, Parroquia Río Negro, Sector El Topo, Estación Cientifica Río Zuñac, Fundación EcoMinga, 01°22.593′S, 78°09.213′W, 1568 m, 26 May 2018 (fl., fr.), L. Jost, F. Recalde & S. Recalde 10600 (QCNE barcode 243978 [1/2], QCNE barcode 243977 [2/2]; isotype: QCNE barcode 243976). – Fig. 9, 19.
Morphological description — Tree up to 20 m tall; young branches glabrous, petioles glabrous to moderately puberulent with simple trichomes, up to 0.13 mm long. Young branches quadrangular and ribbed, 4.5–5.5 mm in diam., nodes with interpetiolar flaps, 2.5–5 mm long. Leaves opposite, slightly anisophyllous. Petioles semiterete and adaxially ribbed, 2.5–5 cm long, with an adaxial projection (scutum) at insertion of petiole with leaf blade, up to 2 mm tall. Leaf blades subcoriaceous, 11.4–26 × 5.6–19.3 cm, ovate to broadly elliptic, apex acuminate, base broadly obtuse to rounded, margin entire, revolute at base, discolorous; venation acrodromous and basal, with two pairs or sometimes three pairs of secondaries (lateral nerves) and an additional pair of faint submarginal veins running up to leaf apex, tertiary (transversal nerves) 29–40 on each side of primary, percurrent, 1.5–14 mm distant from each other, midvein, secondary and tertiary veins impressed, reticulation barely visible on adaxial surface, midvein and secondary veins salient, tertiary veins prominent and reticulation visible or barely visible on abaxial surface; adaxial surface flat, dark green when dry, glabrous; abaxial surface green when dry, glabrous to moderately puberulent with simple trichomes, up to 0.13 mm long. Inflorescences terminal panicles, erect, 17.5–33 × 21–33 cm, multiflorous; axis and peduncle glabrous. Peduncle 5.5–14.5 cm long, quadrangular and slightly ribbed. Main axis 13–26 cm long, quadrangular and slightly ribbed. Paraclades in 4 pairs, proximal 14.5–23.5 cm long, distal 3.5 cm long; flowers in 4- or 5-flowered umbels at ends of branchlets. Bracts foliaceous, persistent, 15.3–20 × 10.3–11 cm, petioles 3–4.5 cm long, shape and indumentum similar to principal leaves. Bracteoles not seen (probably early caducous). Flowers 5–merous, erect, with spreading corollas. Pedicels 6–15 mm long, green, glabrous. Hypanthium 11.5–12 × 18–18.5 mm, campanulate, green to light purple, outer and inner surface glabrous; torus glabrous. Calyx opening regularly, green to light purple, outer and inner surface glabrous; tube 6–8 mm long, entire; with 5 slightly callose dorsal projections, whitish and much lighter than rest of calyx and hypanthium when dry. Petals 40–50 × 33–37 mm, 8.5–9.5 mm wide at base, asymmetrically obovate, apex rounded, margin entire, reddish purple, glabrous. Stamens 10, isomorphic, all bent to one side of flower at anthesis giving flower a zygomorphic appearance; filaments 19–19.5 mm, light reddish purple, flat, glabrous; connectives not prolonged below thecae, purple in thecae, light purple in transition to descending dorsobasal appendage, glabrous, with one descending dorsobasal appendage, 6–7 mm long, triangular, cream; anthers 13–14.5 mm long, lanceolate, purple, glabrous, straight, opening by one dorsally inclined pore, thecae surface smooth surface. Ovary 5–locular, superior, free, 13–14.5 × 7–7.5 mm, ovate and 5-lobed, with apical ring of 5 tooth, c. 1 mm long, reddish purple, 6 mm exceeding hypanthium length, glabrous; style 15.5–16 mm long, reddish purple, glabrous, incurved at apex and opposite to anthers at anthesis; stigma punctiform and minutely papillate, c. 1 mm wide, whitish. Fruits capsular (velatidia), with persistent hypanthium and calyx; mature ovary 13–14.5 × 8.5–11 mm, pyriform, slightly costate, 12–13 mm exceeding hypanthium length; fruiting pedicels 15–17 mm long. Seeds not seen.
Phenology — Flowering occurs in February, June and July and fruiting in February and July.
Fig. 19.
Meriania zunacensis – A: node with interpetiolar flap and adaxial projection on petiole apex; B: terminal fertile branch with inflorescence; C: flower at anthesis, apical view; D: immature fruits. – A–D from R. Fernandez-Hilario & al. 1920. – Photographs by Robin Fernandez.
Distribution and ecology — Meriania zunacensis grows in high-elevation montane forests and elfin forests in Amazonas, Bagua and Bongará provinces in the Department of Amazonas, between 1500 and 2280 m. Populations of this species occur in pristine forests.
Discussion — During the preparation of this work we found specimens that did not correspond to any Peruvian species and we were in the process of describing them as a new taxon. However, the recent publication of Meriania zunacensis made us realize that these Peruvian specimens belonged to this newly described species, although some minor morphological differences do exist expanding some size ranges (see description). Meriania zunacensis was previously known only from Andean forests in Ecuador (Tungurahua province; Fernández-Fernández & al. 2020). We can now add three new localities in the Department of Amazonas in N Peru. Among Peruvian species of Meriania, nodes with interpetiolar flaps occur in M. callosa (see comments under this species for differences), M. megaphylla, M. sanguinea and M. tetragona. However, M. megaphylla has quadrangular winged internodes (vs quadrangular and ribbed in M. zunacensis), leaf blades with cordate bases and bullate adaxial surfaces (vs broadly obtuse to rounded and flat surfaces) and calyces with blunt dorsal projections (vs without projections). Meriania zunacensis can also be distinguished by its petioles with adaxial projections (scutum) (vs abaxial projections; liguliform projections in M. sanguinea and tuberculate projections in M. tetragona), leaf blades with entire margins and revolute at bases (vs serrulate margins and not revolute in M. sanguinea and M. tetragona) and spreading, reddish purple corollas (vs campanulate, deep red corollas in M. sanguinea and M. tetragona). A detailed comparison of M. zunacensis with other related species can be found in Fernández-Fernández & al. (2020).
Specimens examined — Peru: Amazonas, Prov. Amazonas, Dist. Vista Alegre, entre Vista Alegre y La Ventana a Naciento del Río Negro, 06°08′S, 77°18′W, 1500–1640 m, 2 Jul 1998 (fl., fr.), I. Sánchez & al. 9610 (CPUN!, F!); Prov. Bagua, La Peca, 1850–1900 m, 14 Jun 1978 (fl. bud), A. Gentry & al. 23012 (USM!, US!); Prov. Bongará, Dist. Yambrasbamba, inmediaciones de la Estación Biológica Abra Patricia, trochas cercanas a la estación, 05°41′43.40″S, 77°48′47.91″W, 2280 m, 19–20 Feb 2020 (fl., fr.), R. Fernandez-Hilario & al. 1920 (HOXA!, KUELAP!, MOL!, NY!, UPCB!); trocha Lechuza en la Estación Biológica Abra Patricia, 05°41′18.89″S, 77°48′23.68″W, 2123 m, 21 Feb 2020 (fl.), R. Fernandez-Hilario & al. 1938 (HOXA!, MOL!, UPCB!).
Author contributions
The authors contributed as follows: RFH: study conceptualization, data collection, specimen examination and draft preparation; RdPRG and RVE: data collection, specimen examination and draft preparation; LL: specimen examination and illustrations; AAWS: data collection and specimen examination; DPB: draft preparation; LPH: data collection and specimen examination; FAM and RG: study conceptualization, specimen examination and draft preparation. All authors reviewed the results and approved the final version of the manuscript.
Acknowledgements
We thank Wilder Chuquitucto for his invaluable support during our botanical collecting and Luis Torres and Lucero Alfaro for the photos of their collections. We thank the curators of the AMAZ, CPUN, CUZ, HOXA, HSP, HUT, KUELAP, MOL, NY, UPCB and USM herbaria for access to specimens. Frank Almeda (CAS) and an anonymous reviewer provided valuable comments on a previous version of this manuscript. Permission to collect and study these species was given by the Servicio Nacional Forestal y de Fauna Silvestre (SERFOR), no. 061-2020-MINAGRI-SERFOR-DGGSPFFS and no. 079-2016-SERFOR-DGGSPFFS, and the Servicio Nacional de Áreas Naturales Protegidas (SERNANP), no. 007-2017-SERNANP-PNYCh. This project was supported through a fellowship from OTS (Bossuyt-Fund 518) and CAPES/Brazil to RFH.
