Burmeistera Triana, with ∼120 species, is the fourth largest genus of Lobelioideae in the family Campanulaceae (Lammers 2007). Species are found in the understory of cloud forests from Guatemala through northernmost Peru, but are absent in Belize, El Salvador, and Nicaragua. The highest species diversity of Burmeistera occurs in the northern Andes of Colombia and Ecuador (Garzón Venegas et al. 2014; Jeppesen 1981; McVaugh 1949). The genus comprises herbaceous to suffruticose plants that are terrestrial or hemi-epiphytic. As in all Lobelioideae, Burmeistera is characterized by protandrous flowers: anthers are fused into an anther tube which releases pollen through the initial male phase as the style elongates within; the stigma then emerges from this tube, unfolds, and becomes receptive (Erbar and Leins 1995; Leins and Erbar 2006). Flowers are typically green or dark maroon and adapted to bat pollination, although some are yellow or pink, and at least one species is known to be hummingbird pollinated (Muchhala 2006b). Fruits are berries, which are often inflated or brightly colored and spongy.

Burmeistera is a subclade of the centropogonids, a clade that also includes the large Neotropical genera Centropogon C. Presl and Siphocampylus Pohl (Lagomarsino et al. 2014). This clade is unique within Lobelioideae for the combination of its Neotropical distribution, woody habit and corolla tube that is entire, neither fenestrate nor dorsally cleft (Lammers 2002; Muchhala and Lammers 2005). Unlike in Centropogon and Siphocampylus, the monophyly of Burmeistera is strongly supported (Antonelli 2008; Knox et al. 2008; Lagomarsino et al. 2014). Morphological synapomorphies of Burmeistera include a dilated anther orifice and seeds that are much longer than broad (Lammers 1998). Additionally, most species of Burmeistera have ebracteolate pedicels (Lammers 1998). At least two lineages of green-flowered, bat-pollinated Centropogon species are successively sister to Burmeistera; together, this clade is known as the burmeisterids and is defined morphologically by a ventricose, inflated corolla throat (Lagomarsino et al. 2014).

Burmeistera is a taxonomically difficult genus (Wilbur 1975, 1976). This is in part due to the wide overlap of characters between species and morphological variation within species, such as in the widespread B. cyclostigmata Donn. Sm. and B. vulgaris E. Wimm. The last comprehensive taxonomic treatment of the genus was Wimmer's monograph of Lobelioideae for Engler's Das Pflanzenreich (Wimmer 1943), though the infrageneric taxonomy established in Wimmer (1943) does not reflect evolutionary relationships (Muchhala and Lammers 2005; Knox et al. 2008; Lagomarsino et al. 2014). Although a new infrageneric taxonomy is still outstanding, taxonomic knowledge of Burmeistera has substantially improved since Wimmer's treatment. There are now floristic treatments for the genus for most countries in which it occurs, including Guatemala (Nash 1976), Costa Rica (Wilbur 1975), Panama (Wilbur 1976, 1981), Colombia (ongoing), Ecuador (Jeppesen 1981), and Peru (Stein 1987). The ongoing floristic treatment of Colombia alone has resulted in the description of at least 10 new species and several range extensions (Garzón Venegas and González 2012; Garzón Venegas et al. 2012; Garzón Venegas et al. 2014; Garzón Venegas et al. 2013). Additionally, recent research on the pollination biology of Burmeistera has resulted in the description of new species (Muchhala and Lammers 2005; Muchhala and Pérez 2015) and a better understanding of the ecology and evolution of the group (Muchhala and Potts 2007; Muchhala 2003, 2006a, 2006b, 2007).

The Cordillera de Talamanca, shared between Costa Rica and Panama, is home to 21 species of Burmeistera, the highest species diversity outside of the Andean mountains. This mountain range stretches 320 km from the vicinity of San José and Cartago, Costa Rica to just beyond the Costa Rica-Panama border (Janzen 1983). The flora of the Cordillera de Talamanca, which has strong phytogeographical affinities with the northern Andes (Gentry 1982; Kappelle et al. 1992), is extremely diverse, particularly at mid-elevation. Important habitats in the Talamanca mountain range include cloud forests, oak forests, bogs, and the westernmost páramos (Luteyn 1999). A large portion of this cordillera is protected by the Parque Internacional La Amistad (PILA), a UNESCO World Heritage Site shared between Costa Rica and Panama.

Here, we describe two new species of Burmeistera native to the Cordillera de Talamanca: B. monroi and B. serratifolia. We also provide a key to all known species of Burmeistera native to Central America.

Materials and Methods

Herbarium specimens, including types, of Central American Burmeistera were examined at A, CR, GH, INB, MO, NY, PMA, and SCZ (herbarium abbreviations and throughout follow Thiers [2013]). Additional type specimens were accessed from the Global Plants Initiative website ( http://plants.jstor.org/). Material was examined under a Leica Stereo-Zoom 5 binocular microscope. Terminology in the taxonomic treatment and dichotomous key largely follows Wilbur (1975, 1976, 1981). The dichotomous key is adapted from Wilbur (1975, 1976, 1981) and includes the countries of occurrence for each species in parentheses (COL: Colombia; CR: Costa Rica; ECU: Ecuador; G: Guatemala; H: Honduras; P: Panama); these data were obtained from herbarium specimens, as well as from the Tropicos database ( http://www.tropicos.org/).

Taxonomic Treatment

Burmeistera monroi D. Santam. & Lagom., sp. nov.— TYPE: PANAMA. Bocas del Toro: Ridges leading to Río Teribe, NE most ridge of Cerro Fábrega ridge, 09°09′07″N 082°51′52″W, 2,900 m, 07 Mar 2006 (fl), A. K. Monro & S. Knapp 5225 (holotype: PMA!; isotype: BM!).

Terrestrial herb 0.6–1 m in height, with ascending branches, producing white latex; branches 1.5–3 mm in diameter, fistulose, reddish to purple in living material, drying yellowish, indumentum villose with septate trichomes, internodes 1.8–5.5 cm long. Leaves distichous or spirally arranged; petiole 0.4–1.6 cm long, villose; blade 4.9–12.1 × 2.5–3.4 cm, elliptic or narrowly elliptic, apex acuminate, base cuneate, margin dentate, 2 short teeth per cm, round or minutely triangular; venation semicraspedodromous, with 6–12 pairs of lateral nerves, flat and barely visible on the adaxial surface, elevated on the abaxial surface; adaxial surface glabrous; abaxial surface pubescent, especially over the veins. Flowers solitary in the axils of distal leaves, pedicels 1.9–5.7 cm long, ebracteolate, straight, villose, bearing septate trichomes; hypanthium 3–4.7 × 3–5 mm, globose or hemispheric at anthesis, sparsely pubescent, green or green with dark purple; calyx lobes 2.3–5 × 1.2–1.5 mm, oblong to lanceolate with acute or obtuse apex, one central vein, the margins entire or dentate with 2–5 teeth per side, sometimes with marginal ciliate trichomes, glabrous on the adaxial surface, sparsely pubescent on the abaxial surface, erect or slightly recurved; corolla 22–25 mm long, green grading into dark purple or brownish externally, purple and green internally, sparingly to moderately short pubescent externally, glabrous internally, throat not ventricose at anthesis; corolla tube 14–16 × 2–3 mm, straight in anthesis; corolla lobes deflexed-falcate, narrowly linear, with an acute apex, dorsal lobes 8–12 × 1.5–2 mm, lateral lobes 5–7 × 1–1.2 mm, ventral lobe 4–6 × 1–1.2 mm; filament tube 18–21 × 1–1.8 mm, straight, completely glabrous, reddish-purple in living material, exserted between the dorsal corolla lobes 2–3 mm beyond the corolla; anther tube ca. 5–8 × 2–3 mm, purple, largely glabrous, but with appressed sparse pubescence in the suture between individual anthers, the two ventral anthers ca. 5 mm long, with penicillate white hairs at the apex but otherwise glabrous, the three dorsal anthers ca. 6 mm long, glabrous throughout. Berries 0.5 × 0.7 cm when immature (dried), 0.8 × 0.9 cm when mature (dried), globose, inflated, color unknown; seeds 0.5–0.8 mm long, light brown, elliptic. Figures 1–2.

Additional Specimens Examined—COSTA RICA. Puntarenas: Parque Internacional La Amistad, sendero al Valle del Silencio, sector entre el albergue y la línea divisora de aguas, 09°04′00″N, 82°59′00″W, 2,100–2,200, 20 Feb 2006 (fl & fr), D. Santamaría 3909 (GH, INB); Parque Internacional La Amistad. Casa Coca, punto 11, 09°05′61″N, 82°58′66″W, 2,550 m, 04 Apr 2011 (fl & fr). A. K. Monro & D. Santamaría 6986 (BM, GH, INB, MO); Parque Internacional La Amistad. Tararia. Valle del Silencio, 09°06′61″N, 82°58′03″W, 2,500 m, 01 Sep 2001 (fl), E. Alfaro & O. Esquivel 3716 (MO).

PANAMA. Bocas del Toro: Cordillera de Talamanca, headwaters of the Río Culubre, 6 airline km NW of the peak of Cerro Echandi on the Costa Rican-Panamanian international border, 2,450–2,600 m, 02–03 March 1984 (fl & fr), G. Davidse et al. 25196 (CR, DUKE[image]).

Distribution and Habitat—Burmeistera monroi is restricted to the Parque Internacional La Amistad, where it is found on both the Costa Rican and Panamanian sides of this protected area. It grows in cloud forests on the Caribbean slope of the Cordillera de Talamanca between 2,100–2,900 m. The elevational range occupied by Burmeistera monroi is high for its genus, though not exceptional.

Phenology—Specimens of Burmeistera monroi were collected in flower in February–April and September. All except the September collections were also in fruit. This suggests a long flowering season, but phenology in the rest of the year is unknown.

Etymology—It is an honor to dedicate this new species to the British botanist Alexandre K. Monro (1968-), investigator at the Kew Royal Botanic Gardens in London and world authority of Urticaceae. Monro has led many botanical expeditions into the Cordillera de Talamanca and Parque Internacional La Amistad in Costa Rica and Panama that have substantially increased our understanding of the biodiversity in this species-rich region. During one of these trips, Monro collected the type specimen of the species that we describe here in his honor.

Notes—Burmeistera monroi is distinguished by its straight, narrow, sparsely pubescent corolla with narrowly linear corolla lobes and a non-ventricose throat. It is most similar to B. nigropilosa Luteyn ex Garzón & F. González from Antioquia, Colombia (Garzón Venegas and González 2012), but can be distinguished by its glabrous to sparsely-pubescent, smooth leaves (versus densely pubescent, bullate leaves), ebracteolate pedicels (versus bracteolate), dark purple or brown corolla tube that grades distally to green (versus green), and whitish and sparse corolla pubescence (versus dark or hyaline and dense).

Among Central American species, Burmeistera monroi is most similar to B. chirripoensis Wilbur, from which it can be distinguished by its dark purple to brown corolla tube grading into green (versus green), the corolla throat that is not ventricose (versus ventricose), and largely glabrous anthers (versus densely pubescent throughout). It is also similar to B. virescens (Benth.) Benth. & Hook. f. ex Hemsl. from relatively low elevations, ca. 500–2,000 m, in Guatemala and Honduras due to its narrow corolla tube, but can be readily distinguished by its villose stems (versus glabrous or puberulent), elliptic or narrowly elliptic leaves (versus oblong-elliptic to ovate), globose to hemispheric hypanthium at anthesis (versus obconic), corolla throat that is not ventricose (versus ventricose), and corolla tube that is dark purple to brown grading into green (versus green). Burmeistera monroi is vegetatively similar to B. estrellana, but differs in its corolla that is not ventricose (versus ventricose) with linear lobes (versus deltoid).

Burmeistera monroi is among three known species of Burmeistera in Central America with inflated fruits. The other species are B. vulgaris and B. glauca (E. Wimm.) Gleason. The former, B. vulgaris, is a widespread species that is readily distinguished from B. monroi by its ventricose corolla throat (versus not ventricose) and cylindric hypanthium (versus globose or hemispheric). The latter, B. glauca, can be distinguished from B. monroi by its hemi-epiphytic to epiphytic habit (versus terrestrial), glabrous corolla (versus sparsely to moderately pubescent), and oblong-ovoid berry (versus globose).

Fig. 1.

Burmeistera monroi. A. Habit with flower buds, flower, and fruit. B. Flower in female phase. All drawings by L. Lagomarsino based on A. K. Monro 7142.

Fig. 2.

Burmeistera monroi, photographs from field collections. A. Habit. B. Flower in female phase, lateral view. C. Flower in female phase, frontal view with detail of stigma and anthers. D. Flower in male phase, lateral view. E. Flowering branch with developing fruits. F. Abaxial leaf surface. All photos are of A. K. Monro 7142 except D, which is of A. K. Monro 6986. Photos by A. K. Monro.

Burmeistera monroi is also among few species of its genus that does not have a ventricose corolla throat (as in e.g. B. serratifolia, Fig. 3D), thought to be an adaptation to bat pollination in some species (Muchhala 2006b). This species' corolla morphology (a long, straight corolla tube with falcate corolla lobes and a non-ventricose throat) is quite similar to the brevilimbatid subclade of Centropogon (Lagomarsino et al. 2014), which includes the hummingbird-pollinated C. valerioi Standl. (Colwell et al. 1974) and C. ferrugineus (L. f.) Gleason from Costa Rica; these species are easily distinguished from B. monroi by their more robust, scandent subshrub habit (versus terrestrial herb less than 1 m in height), generally bright orange corolla tubes with yellow limb (versus brown grading into green), and a constricted anther orifice (versus dilated). The pollinator of B. monroi is unknown.

Burmeistera serratifolia Lagom. & D. Santam., sp. nov.— TYPE: PANAMA. Chiriquí: Ridges above and to W of Quebrada Alemán, trail to town of Fortuna, 08°45′N, 82°13′W, 1,200–1,500 m, 13 Aug 2000 (fl), S. Knapp & J. Mallet 9226 (holotype: PMA!; isotype: SCZ!).

Epiphytic herb producing white latex; branches 2.5–3 mm in diameter, fistulose, sparsely puberulent with simple trichomes, internodes 1.5–3 cm long. Leaves spirally arranged; petiole 0.6–1.5 cm long, sparsely pubescent; blade 10.2–15 × 1–1.7 cm, narrowly oblong-lanceolate, apex acuminate, base cuneate, sometimes slightly decurrent and asymmetric, margin strongly irregularly serrate, 15–17 conspicuous triangular teeth per cm; venation semicraspedodromous, lateral nerves 13–20 per side, flat and little visible on the adaxial surface, elevated on the abaxial surface; adaxial surface glabrous; abaxial surface glabrous except on the veins, which are pubescent. Flowers solitary in the axils of upper leaves, which are sometimes reduced in size compared to mature leaves not associated with flowers; pedicels 7–11.2 cm long, straight or slightly curved towards the apex, ebracteolate, glabrous or sparsely pubescent, the trichomes not septate; hypanthium 9–11 × 2–4 mm, campanulate at anthesis, glabrous or sparsely pubescent with simple trichomes; calyx lobes 3–4.5 × 1–4.5 mm, oblong-lanceolate to triangular with acute apex, with one almost indistinct central vein, margins serrate, with 3–5 teeth per side, glabrous on both surfaces, straight or slightly curved; corolla ca. 21–40 mm long, green, glabrous on all surfaces, throat ventricose; tube 5–11 × 2–4.5 mm, straight; lobes oblong, falcate, with an acuminate or acute apex, dorsal lobes 13–15 × 3.5–5 mm, lateral lobes ca. 14 × 4 mm, ventral lobe ca. 14 × 2 mm; filament tube ca. 31 × 1.1 mm, straight in the proximal half and curved towards the distal end, glabrous except towards the apex where it is strigose, exserted between the pair of dorsal lobes ca. 15 mm; anther tube ca. 5 × 3 mm, glabrous or minutely pubescent, the two ventral anthers ca. 3–4 mm long, glabrous throughout, the three dorsal anthers ca. 5 mm long, glabrous throughout. Berries 1.8 × 0.6 cm (possibly not mature), more or less cylindrical, calyx lobes persistent, glabrous; seeds not seen. Seedlings produce finely divided leaves (information from label). Figure 3.

Distribution and Habitat—Burmeistera serratifolia is endemic to Panama, where it grows in premontane and montane forests on the Caribbean slope of the Cordillera de Talamanca between 1,200–1,500 m in elevation. It is only known from the type, collected in the Reserva Forestal Fortuna, Chiriquí, Panama.

Phenology—Flowers and fruits were collected from Burmeistera serratifolia in August, but phenology is otherwise unknown.

Etymology—This species' epithet refers to the characteristic serrate leaf margins of this species.

Notes—This species is exceptional for its oblong-lanceolate leaves with strongly serrate margins. Burmeistera serratifolia is most similar to B. chiriquiensis Wilbur from western Panama and eastern Costa Rica, with which it shares its oblonglanceolate leaves; it can be distinguished by its prominently and irregularly serrate leaf margins with more than 15 conspicuous teeth/cm (versus shallowly dentate leaf margins with one to two inconspicuous teeth/cm), secondary and tertiary venation that is easily distinguished and reticulate (versus secondary and tertiary venation that is not prominent), acuminate leaf apex (versus caudate), pedicel 7.0–11.2 cm long (versus ca. 3 cm long), campanulate hypanthium (versus obconic), filament tube 30 mm long (versus 23 mm long), and the glabrous tips of the ventral anthers (versus densely pilose). Burmeistera intii Gómez-Laur. & L.D. Gómez also has oblong-lanceolate leaves; however, they are less than 8 cm long (versus 10–15 cm in B. serratifolia). Burmeistera silencioensis Wilbur (ined.), which is soon to be validly published in conjunction with the Manual de las Plantas de Costa Rica, also produces elongate leaves. However, B. serratifolia can be distinguished from this entity, which would also belong near the third couplet of the key below, by its irregularly serrate leaf margins (versus serrulate), acute leaf apices (versus acuminate to caudate), sepals with serrate margins (versus inconspicuously serrulate), and filament tube exserted 1.5 cm beyond the corolla (versus included or exserted less than 5 mm). The following specimens of B. silencioensis from Costa Rica and Panama were examined to compare to B. monroi: A. K. Monro 7117 (INB), D. Santamaría-Aguilar 9093 (INB), and T. Antonio 1608A (DUKE [image]). It is not our intention to validly publish this species name here.

Fig. 3.

Burmeistera serratifolia. A. Habit with flower buds, flower, and fruit. B. Detail of leaf margin and venation. C. Flower bud. D. Flower in male phase. All drawings by L. Lagomarsino based on the holotype.

Among Central American species, Burmeistera serratifolia shares its finely divided juvenile leaves only with B. mcvaughii Wilbur, from which it is readily distinguished by its longlanceolate leaves with serrate margins bearing more than 15 teeth/cm (versus elliptic with serrulate to denticulate margins bearing 6–8 teeth/cm) and campanulate hypanthium (versus obconic). Additionally, two specimens currently identified as B. dendrophila (L. E. Skog 4056 [MO] and B. Hammel 6199 [MO]) also produce finely divided young leaves, though this does not appear to be common in this species.