Typus: Madagascar. Prov. Toamasina: Analanjirofo Region, Ambinanihely, Camp I, Befontsimanta, 15°29′53″S 49°22′56″E, 919 m, 21.XI.2003, fl, Antilahimena 2340 (holo-: MO-6306540!; iso-: K, P, SUNIV!, TAN).

Haec species a congeneris stipulis bilobis grandibus marginibus plerumque serratis, foliis grandibus atque inflorescentia grandi axibus prolongatis spiciformibus distinguitur.

Woody lianas or climbing shrubs, climbing to 8 m high; stems puberulous, quadrangular. Leaves opposite; blades elliptic, ovate, or obovate, 12-24 × 6-9.5 cm, at base acute to cuneate, at apex acuminate with tips 3–10 mm, drying papery to chartaceous, adaxially glabrous, abaxially glabrous to puberulous on lamina and puberulous to strigillose or strigose on principal veins, with margins plane; secondary veins 12 to 18 pairs, looping to interconnect with each other near margins, adaxially costa and secondary veins plane to prominulous and tertiary venation prominulous and rather loosely reticulated, abaxially costa and secondary veins prominent and intersecondary and tertiary venation prominulous. Petioles 10–30 mm, puberulous to glabrescent. Stipules interpetiolar, persistent at least on distalmost 3 or 4 nodes, ovate to triangular or elliptic, 7–13 mm, abaxially puberulous to glabrescent, at apex obtuse to acute and shortly 2-lobed, margins entire to usually serrate or sparsely shortly laciniate. Inflorescences terminal and in axils of uppermost leaves, paniculate, pyramidal in outline, 15-38 × 12-26 cm (including peduncles), multiflowered (ca. 60 to 200 flowers), branched to 2 to 3 orders, with principal axes spiciform, with axes puberulous, with basalmost secondary axes often subtended by ovate foliaceous bracts (or reduced leaves) 5.5-8.5 × 4-6.5 cm on stipes (or petioles) 0.3–1.5 cm; other bracts linear to triangular, 0.3–3 mm. Flowers in dichasial groups of 2 to 5 with terminal flower sessile and others subsessile to pedicellate on pedicels up to 1 mm, with floral biology (i.e., distyly vs. monomorphy) unknown; hypanthium (i.e., ovary portion) ellipsoid-obconic, ca. 0.8 mm, densely puberulous. Calyx limb divided nearly to base, densely puberulous, lobes 5, narrowly triangular, ca. 1 mm, acute. Corolla slenderly funnelform to salverform, purple, externally glabrous, internally sparsely pilose in throat and upper 2/3 of tube, tube 10–10.5 mm, ca. 1 mm diam. at base, ca. 1.5 mm diam, at throat, at base fenestrate with 5 slits, each slit 1.5– 2 mm, lobes 5, narrowly triangular, ca. 3 mm, acute and shortly thickened at apex; stamens 5, inserted in throat, anthers 1.2– 2 mm, purple, exserted on filaments ca. 4 mm. Stigmas 2, linear, ca. 2 mm, included and positioned above middle of corolla tube, style ca. 5 mm. Capsules subglobose to somewhat oblate, 3 × 3-3.2 mm, stiffly chartaceous, densely puberulous, dehiscent through flattened to broadly triangular beak portion (i.e., top part inside calyx limb), often also splitting from apex for 1/3–1/2 of body. Seeds irregular in shape but generally elliptic to rectangular, 0.3–0.8 mm, flattened, with circumferential wing shortly laciniate and usually elongated on one side.

Names. — The scientific name of this robust handsome species is created here to honor Mr. Patrice Antilahimena, collector of the type specimen and one of the Missouri Botanical Garden's resident field botanists. Mr. Antilahimena has extensively documented Madagascar's flora with excellent specimens collected during numerous explorations made throughout the island. No vernacular name has been noted in the information available.

Habitat and distribution. — This species is documented from humid forests at 600–1125 m in eastern Madagascar, in northern Toamasina Province (Analanjirofo Region) in the area of the Masoala Peninsula and Baie d'Antongil (Fig. 2, humid bioclimatic zone). This species is known from a limited geographic distribution; see Madagascar Catalogue (2013) for detailed distribution mapping.

Conservation status. — Danais antilahimenae has an EOO of 134 km², which meets the criterion for Endangered; an AOO <500 km², which also meets the criterion for Endangered; and three subpopulations. The species is known from three localities, only one of which falls inside the boundaries of a currently protected area (Masoala National Park). The habitat of this species is already significantly fragmented and expected to diminish further in quality. Danais antilahimenae is assigned a preliminary conservation status of Endangered due to its limited distribution and threatened habitat [EN Blab(i,ii,iii,iv)+2ab(i,ii,iii,iv)].

Notes on morphology and similar species. — This new species is characterized by its relatively large leaves (for Danais), its rather large stipules with shortly laciniate to usually serrate margins, its relatively very large inflorescences (for Danais) with the secondary axes prolonged and spiciform, its medium-sized flowers with purple corollas, and its small fruits. The stipules of this species are unusual in Danais, and similar only to those of D. rakotovaoi; see the discussion of that second species below for the distinctions between these. Only one flowering collection has been seen, with flowers that resemble the short-styled form of distylous species of Danais. The presence of the foliaceous bracts or reduced leaves at the base of the inflorescences is consistent in the specimens studied. The overall inflorescence arrangement of D. antilahimenae (apart from the narrowly spiciform secondary axes) and its small fruits are similar to the species that Puff & Buchner (1994) included in their informal “Danais microcarpa group”. However the species included in that group are all characterized by white to yellow, shorter corollas, with the tubes 1–5.5 mm long, whereas the flowers of D. antilahimena are more similar to those of another Malagasy species, D. nigra Homolle, which has black to dark purple corollas and well developed corolla tubes. Danais nigra differs from D. antilahimenae in its short (ca. 1 mm long) triangular stipules, its regularly cymose inflorescence axes, and its longer corollas (tubes 11–20 mm long).

Paratypi. — Madagascar. Prov. Toamasina: Analanjirofo, Maroantsetra, Antsirabesahatany, Anjiahley, 15°26′30″S 49°32′19″E, 600 m, 27.XII.2002, fr., Antilahimena, Pascal & Ramaroson 1627 (MO!); Masoala National Park, E slope of Ambohitsitondroinan' Mahalevona, ESE of village of Mahalevona, 15°26′00″S 49°57′34″E, 1125 m, 23.II.2003, fr., Lowry, Schatz & Be 6097 (K, MO!, P, TAN).

Typus: Madagascar. Prov. Fianarantsoa: Vatovavy-Fitovinany Region, E de Fianarantsoa, Parc National de Ranomafana, Parcelle III, Talatakely, 21°16′S 47°25′E, IV-V.1992, fl., Rakoto 29 (holo-: MO-6087991!; iso-: G[G00369981]).

Haec species a congeneris foliis parvis ut videtur distichis atque inflorescentia brevi pauciflora terminali distinguitur.

Woody lianas or climbing shrubs, apparently rather extensively twining, climbing to at least 6 m high; stems densely puberulous, rounded, with principal stems elongated and mostly leafless, with leaves and flowers mostly borne on shorter lateral stems. Leaves opposite or rarely ternate; blades elliptic to broadly elliptic or ovate, 0.5-1.2 × 0.3-1 cm, at base cuneate to obtuse, at apex obtuse to acute or shortly acuminate with tips 1-1.5 mm, drying papery to chartaceous and often rather shiny, glabrous on both surfaces, with margins thinly revolute; secondary veins 3 or 4 pairs, free or sometimes weakly looping to interconnect with each other near margins, adaxially costa plane or prominulous and secondary veins and some tertiary veins thinly prominulous, abaxially costa prominent and secondary veins and some tertiary veins thinly prominulous. Petioles 0.5–1 mm, glabrous to puberulous. Stipules interpetiolar, deciduous below 5 to 8 distalmost nodes, triangular, ca. 1 mm, abaxially densely puberulous, acute. Inflorescences terminal and in axils of uppermost leaves, cymose, cylindrical to rounded in outline, 1-2.5 × 0.8-2.5 cm (including peduncles), few- to several-flowered (ca. 3 to 15), branched to 1 or 2 orders, with axes cymose, glabrous to puberulous; bracts narrowly triangular, 1–2 mm. Flowers in dichasial to umbelliform groups and all pedicellate on pedicels 1–3 mm, distylous; hypanthium oblate to ellipsoid, 0.3–0.8 mm, glabrous. Calyx limb divided nearly to base, glabrous, lobes 4 to 6, narrowly triangular to deltate or ligulate, 0.3–0.8 mm, acute to rounded, with lobes generally equal or with 1 lobe slightly larger on some flowers. Corolla funnelform to funnelform-salverform, white becoming yellowed with age, externally glabrous, internally moderately to densely pilosulous in throat and upper 1/2 of tube, tube 3–3.5 mm, 1–1.2 mm diam. at base, 1–1.3 mm diam. at top, at base entire (i.e., not fenestrate), lobes 4 to 6, narrowly triangular, 1.5–2 mm, acute and smooth at apex. Stamens 4 to 5, inserted in corolla throat, anthers creamy white, in short-styled flowers ca. 0.8 mm and exserted on filaments 2.5–3 mm, in long-styled flowers ca. 0.8 mm, sessile, and partially exserted. Stigmas 2, linear, in short-styled flowers ca. 1 mm and included, with style ca. 2 mm, in long-styled flowers ca. 2 mm and exserted, with style ca. 5 mm. Capsules subglobose, 1.5–3 mm in diam., stiffly chartaceous to woody, glabrous, dehiscent from apex through top 1/3–1/2 of body, with beak portion flat to rounded. Seeds not seen.

Names. — The scientific name created here for this species refers to the apparently distichous leaf arrangement that is distinctive, as noted below. The vernacular name “Vahimavo” was noted on Rakoto 29, and is probably in the Betsileo dialect. Translated into English this means “yellow liana”.

Habitat and distribution. — This species is documented from humid forests at ca. 850–1300 m in east-central Madagascar, in the provinces of Fianarantsoa, in Ranomafana National Park (Vatovavy-Fitovinany Region), and Toamasina, in the Alaotra-Mangoro Region and in the region of Andasibe/Moramanga (Fig. 4, humid bioclimatic zone).

Conservation status. — Danais disticha has an EOO of 8609 km²,which meets the criterion for Vulnerable; an AOO of <500 km² which meets the criterion for Endangered; and three subpopulations. The species is known from four collections in three localities, and only one of those falls inside the boundaries of a currently protected area (Ranomafana National Park). The species was collected in a small forest remnant located about six kilometers outside of a second protected area (Analamazoatra Special Reserve) in 1997, so it is possible that extant populations occur within the adjacent Reserve or in the nearly contiguous Mantadia National Park. The habitat of this species is already significantly fragmented and expected to diminish further in quality. Danais disticha is assigned a preliminary conservation status of Vulnerable due to its limited distribution and threatened habitat [VUB1ab(i,ii,iii,iv)+2ab (i,ii,iii,iv)].

Notes on morphology, biology and similar species. — Danais disticha is characterized by its growth patternm, with prolonged and mostly leafless principal stems and shorter lateral stems bearing numerous regularly arranged small leaves; its short triangular stipules; its relatively small inflorescences that are terminal and sometimes also produced in the adjacent uppermost leaf axils; its pedicellate flowers; its calyx and corolla with a variable number of lobes (four to six); and its relatively small capsules. The regularly arranged leaves appear to be at least weakly distichous, even though the leaf arrangement in the genus is basically decussate. Such an arrangement requires twisting of the intemodes to alter this decussate arrangement, and is found in some Rubiaceae. This apparent distichous arrangement may be only an artifact of specimen preparation, and field observations are needed to confirm the morphology of this species.

Only two flowering collections have been seen: one has short-styled flowers (Turk & al. 454) with variously four or five calyx and corolla lobes but consistently five stamens; the other has long-styled flowers (Rakoto 29) with variously four or five calyx and corolla lobes and consistently four stamens. Variation in calyx and corolla lobe number within Danais species was previously documented by Puff & Buchner (1994). Only two apparently mature capsules have been examined, and no mature seeds of this species were found; however all of the other characters, including the climbing habit, agree with Danais and this species is therefore included in this genus. Within Danais, this new species is similar to those included in Puff & Buchner (1994)'s informal “Danais microcarpa group”, in particular D. microcarpa Baker and D. ligustrifolia Baker. However this new species differs from these and other species of Danais in its consistently smaller leaves and characteristic branching arrangement.

Paratypi. — Madagascar. Prov. Fianarantsoa: Vatovavy-Fitovinany, Ranomafana National Park, Parcelle 3, S of National Road 25 at 7 km W of Ranomafana, Talatakely trail system, 21°15′30″S 47°25′00″E, 950–1150 m, 7.V.1993, fl., Turk & al. 454 (MO!). Prov. Toamasina: Alaotra-Mangoro, along Route National no. 2 (Antananarivo to Tamatave [Toamasina]), 6 km due SE of Andasibe (Permet), above the river near Anevoka, 18°56′S 48°27′E, 850 m, 24.XI.1997, y. fr., Davis, Andriantiana, Gower & Malcomber 1157 (G, K, MO!, TAN); Moramanga, Ambongabe, Ambodikija [Anjozorobe], 18°29′33″S 48°00′50″E, 1300 m, 4.IV.2005, y. fr, Rabehevitra & al. 1408 (MO!).

Typus: Madagascar. Prov. Toamasina: Analanjirofo Region, Ankirindro Massif, slopes above the village Ambodivato, ca. 5 km NW of Ambinanitelo along the Vohimaro River, 15°19′13″S 49°33′29″E, 150 m, 20.XI.2002, fr., Schatz & Antilahimena 4007 (holo-: MO-5989728!; iso-: BR, K, P, TAN).

Haec species a congeneris pubescentia hispida, foliis ternatis, stipulis reflexis laciniatis, inflorescentia terminali, pedicellis longis atque lobis calycinis longis linearibus distinguitur.

Woody lianas or climbing shrubs, climbing to 7 m high; stems moderately to densely hispid or pilose, subterete. Leaves opposite or temate with arrangement often variable on a single stem; blades obovate to oblanceolate or elliptic, 2.5-8.5 × 1-3 cm, at base acute to cuneate, at apex acute to acuminate with tips 3–10 mm, drying papery, adaxially moderately hispid to strigose throughout, abaxially moderately to densely hispid to strigose with pubescence denser on principal veins, with margins plane; secondary veins 7 to 11 pairs, not looping to inter-connect with each other, adaxially costa and secondary veins prominulous and remaining venation plane, abaxially costa prominent, secondary veins prominulous, intersecondary veins inconspicuous or hardly developed, and tertiary venation loosely reticulated and plane to prominulous. Petioles 3–7 mm, densely hispid to pilose. Stipules interpetiolar, generally persistent with leaves and becoming reflexed, deeply laciniate, with unlobed basal portion truncate to triangular, 1–2.5 mm, with laciniae or lobes 3 to 6, narrowly triangular, 2–4 mm, acute to acuminate, entire to ciliate. Inflorescences and flowers not seen. Infructescences terminal and sometimes also axillary at distalmost 1 to 4 nodes, cymose, rounded in outline, 3-5 × 2-6 cm (including peduncles and fruits), several-flowered (2 to 5), with fruits umbellate or usually with primary axis developed and fruits produced at 2 nodes, with axes hispid to pilose; bracts narrowly elliptic to narrowly triangular or stipuliform, 5–13 mm. Capsules in umbelliform groups of 2 to 5 and all pedicellate on pedicels 15–26 mm, subglobose to oblate and laterally somewhat flattened, 8-12 × 10-12 mm, stiffly chartaceous to thinly woody, moderately to densely pilose to hispid, dehiscent from apex for 1/4–1/2 of body, beak portion flat to broadly conical, with persistent calyx limb divided nearly to base, hispid, lobes 5, narrowly triangular, 7–14 mm, subequal or unequal by up to 1/3 on an individual fruit, acute to acuminate. Seeds elliptic to suborbicular, 2–2.5 mm, flattened, with circumferential wing subentire to weakly dentate and with 1 deep incision.

Names. — The scientific name created here for this species refers to the laciniate stipule form, which is unusual in the genus. The vernacular name “Vahidambo” was noted on Antilahimena 2627, and is probably in the northern Betsimisaraka dialect. This name translated into English means “pig liana” or “wild pig vine”.

Habitat and distribution. — This species is documented from humid forests, at least sometimes in highly disturbed sites, at 150–298 m in eastern Madagascar, in Toamasina Province (Analanjirofo Region, Fig. 5, humid bioclimatic zone).

Conservation status. — An EOO cannot be calculated for Danais laciniata because the species is known only from two localities. Its AOO is very restricted, certainly <10 km², which meets the criterion for Critically Endangered. The two localities where this species is known are ca. 4 km apart, and neither falls within Madagascar's current system of protected areas. Vegetation at one of the localities was highly fragmented and disturbed in 2002 according to the label information, and the other site is most likely similarly degraded. The habitat quality is certainly expected to worsen in the future, and Danais laciniata is assigned a preliminary conservation status of Critically Endangered due to its limited distribution and threatened habitat [CR B2ab(i,ii,iii,iv)].

Notes on morphology, taxonomic identity and similar species. — Danais laciniata can be recognized by its hispid or pilose pubescence, its leaves that are ternately arranged on at least some nodes and with the blades generally widest above the middle, its laciniate reflexed stipules, its rather lax umbelliform infructescences, its well developed persistent calyx lobes, and its relatively large fruits and seeds. Although the inflorescences and flowers of this species have not been seen, the fruit characters along with the climbing habit support its classification in Danais and the combination of the distinctive characters listed above distinguish D. laciniata from all other Danais species. The relatively long, perhaps flexuous pedicels also appear to be distinctive for this species, but in Danais the fruiting pedicels are frequently much longer than flowering pedicels (e.g., D. vestita Baker), so details of the inflorescences cannot necessarily be inferred from the infructescences.

These plants may be the same as the fruiting specimen J. S. Miller & al. 3326 that was studied by Puff & Buchner (1994: 44), but neither that collection nor duplicates have been located. Puff & Buchner (1994) included that specimen provisionally in their circumscription of Danais vestita Baker but considered it anomalous due to its ternate leaves, sparser pubescence that dried whitish rather than rusty brown, fewer-flowered inflorescences, and more northern collection locality. Additional specimens of both D. vestita and this new species are now available and clarify that the distinctive features cited by Puff & Buchner (1994) for each of these are consistent. Danais vestita differs from D. laciniata in its pubescence, which is densely pilosulous or hirtellous with shorter trichomes; its leaf blades that are widest below the middle and truncate to cordulate at the base; its stipules that are erect or sometimes weakly spreading; and its inflorescences that are mainly axillary with the bracts linear and generally 1—5 mm long.Specimens of D. laciniata will be identified by Puff & Buchner (1994)'s key as D. andribensis Homolle, of central and southern Madagascar; however D. andribensis differs from D. laciniata in its pubescence, which is pilosulous to puberulous or entirely lacking, its opposite leaves with the blades widest below the middle and rounded to cordulate at the base, its consistently bilobed stipules, and its smaller capsules (4–8 mm in diam.).

Paratypi. — Madagascar. Prov. Toamasina: Analanjirofo, Maroantsetra, Ambinanitelo, Marovovonana, 15°19′34″S 49°31′15′E, 298 m, 29.VIII.2004, fr., Antilahimena 2627 (MO!, P, TAN).

Typus: Madagascar. Prov. Toamasina: Analanjirofo Region, Masoala Peninsula, S of Ambanizana, Andranobe, Piste A, 15°41′S 49°58′E, 50 m, 12.II.1999, fl., Hoffmann, Robinson, McPherson & Harimalala 36 (holo-: MO-5938276!; iso-: G[G00369979], K, TAN).

Haec species a congeneris stipulis aristatis circum caulem breviter connatis, foliis satis grandibus, inflorescentia axillari atque floribus sicut fructibus papyraceis satis parvis pedicellis gracilibus insidentibus distinguitur.

Woody lianas or climbing shrubs, climbing to 6 m high; stems glabrous, rounded or weakly laterally flattened. Leaves opposite; blades elliptic to obovate, 6.5-19 × 3-11 cm, at base cuneate to obtuse, at apex rounded to obtuse or acute and sometimes abruptly acuminate with tips 2–10 mm, drying chartaceous, glabrous on both surfaces, with margins plane; secondary veins 5 to 11 pairs, not looping to interconnect with each other, with intersecondary veins not, shortly, or occasionally well developed, adaxially costa prominulous, secondary veins plane, and laxly reticulated tertiary venation prominulous, abaxially costa and secondary veins prominent, laxly reticulated tertiary venation prominulous, and densely reticulated quaternary venation plane to thickened or prominulous. Petioles 15–28 mm, glabrous. Stipules shortly united around stem, rather quickly deciduous, triangular, 4–5 mm, abaxially puberulous to glabrous, acute to acuminate or weakly aristate, margins ciliolate to entire. Inflorescences axillary with leaves or sometimes borne in axillary arrangement at nodes below leaves, paniculiform, pyramidal in outline, 6-11 × 3-10 cm (including peduncles), multiflowered (ca. 35 to 60), branched to 2 or 3 orders, with axes cymose, puberulous to glabrous; bracts narrowly triangular to narrowly ligulate, 0.8–4 mm. Flowers in umbelliform groups of 5 to 9 and all pedicellate on pedicels 1–3 mm, with floral biology unknown; hypanthium subglobose to ellipsoid, ca. 1 mm, glabrous. Calyx limb divided nearly to base, lobes 5, triangular, 0.3– 0.8 mm, acute. Corolla slenderly salverform, pale green on tube and bright orange on lobes, externally and internally glabrous, tube ca. 6 mm, ca. 0.5 mm diam. at bottom and at top, at base fenestrate with 5 slits, each slit 0.3–0.5 mm, lobes 5, ligulate to narrowly triangular, ca. 3 mm, acute and smooth at apex. Stamens 5, inserted in corolla throat, anthers black, ca. 2 mm and exserted, filaments ca. 8 mm. Stigmas 2, linear, 3–5 mm, positioned in upper part of corolla tube with tips exserted, style ca. 4.5 mm. Capsules ellipsoid to oblate and laterally flattened, 3-4 × 3.5-5 mm, woody to stiffy chartaceous, glabrous and sparsely to moderately granular, dehiscent from apex for 1/4–1/2 of body, beak broadly triangular to rounded. Seeds generally lenticular, 0.5–0.8 mm, flattened, with circumferential wing irregular (i.e., not entire and smooth) and often reduced.

Names. — This species is so far only known from the Masoala Peninsula, and the scientific name created here for it refers to this locality. No vernacular name is noted in the information available.

Habitat and distribution. — This species is documented from humid forests at 0–400 m in eastern Madagascar, on the Masoala Peninsula in Antsiranana Province (SAVA Region) and in Toamasina Province (Analanjirofo Region; Fig. 5, humid bioclimatic zone).

Conservation status. — Danais masoalana has an EOO of 159 km², which meets the criterion for Endangered; an AOO of <500 km², which also meets the criterion for Endangered; and three subpopulations. The species is known from four collections in two localities; one locality falls inside the boundaries of one protected area (Masoala National Park). The general habitat of this species is already significantly fragmented and expected to diminish further in quality. Danais masoalana is assigned a preliminary conservation status of Endangered due to its limited distribution and threatened habitat [EN B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv)].

Notes on morphology, biology and similar species. — Danais masoalana is characterized by its relatively large leaves (for Danais) with the quaternary venation closely reticulated to form narrowly rectangular areoles on the abaxial surface; its stipules that are shortly united around the stem; its axillary multiflowered inflorescences; its medium-sized orange flowers with the anthers exserted on well developed filaments; and its relatively small fruits usually with a granular surface. Only one flowering collection has been seen, with flowers that resemble the short-styled form of distylous Danais species.

This new species is similar in general aspect to D. rhamnifolia Baker, which is found in the same region; however D. rhamnifolia differs in its usually smaller leaves, with the blades 2-11 × 1-5.5 cm and the petioles 2–17 mm long; its interpetiolar, shorter stipules, 1–2.5 mm long; its usually terminal inflorescences, although these may sometimes also be home in the uppermost leaf axils; its smaller corollas, with the tube 2.5– 5 mm long and the lobes 1.5–2.5 mm long; and its shorter filaments, 2–4.5 mm long. Danais masolana is also similar to D. magna Puff & R. Buchner, which is also found in the same region; however D. magna differs from this new species in its smaller leaves, 7-11 × 2.5-6 cm, with the densely reticulated tertiary and quaternary venation forming subcircular areoles on the lower surface; its shorter inflorescences, 1–3 cm long, with the flowers all sessile to subsessile and without developed secondary axes; its shorter filaments, 5–6 mm long; and its woody fruits with their bases or their short stipes or pedicels (to ca. 1 mm long) significantly thickened, so the fruits sometimes appear fused together. Puff & Buchner (1994) did not see the fruits of D. magna, but these have been documented by recent collections (e.g., Antilahimena & al. 1147, MO!, see image at Tropicos, 2013) and resemble those of D. aurantiaca Homolle. Danais magna is also notable for its habit, which was reported by Puff & Buchner (1994) to be a liana climbing 18 m or more into the forest canopy; all the specimens seen of D. masoalana were gathered from much smaller plants.

Paratypi. — Madagascar. Prov. Antisiranana: SAVA, Masoala Peninsula, W of Ambohitralanana, near Sahafary, 15°16′S 50°22′E, 100 m, fr., 20.VIII.1977, McPherson 17126 (MO!). Prov. Toamasina: Analanjirofo, S of Ambanizana, Andranobe, Piste A, 15°41′S 49°58′E, 205 m, 16.11.1999, y. fr., Hoffmann, Robinson, McPherson & Harimalala 54 (K, MO!, TAN); Parc National de Masoala, Ambanizana, 15°37′S 49°58′E, 0–400 m, 2.IV.1996, y. fr., Aridy & Moïse 227 (MO!).

Typus : Madagascar. Prov. Antsiranana: SAVA Region, Andapa, Doany, Andranomololo, forêt de moyenne altitude située à 10 km au Sud Ouest du village d'Andranomololo, Andramanalana, 14°29′55″S 49°33′43″E, 1098 m, IV.2006, fl., Rakotovao & al. 3222 (holo-: MO-6082545!; iso-: P, TAN).

Haec species a congeneris stipulis grandibus marginibus serratis usque breviter multifidis, inflorescentia axillari floribus in cymas densas rotundatas dispositis atque corolla violacea 9–10 mm longa distinguitur.

Woody lianas or climbing shrubs; stems to 6 m long, densely strigillose to glabrous, rounded. Leaves opposite; blades obovate or oblanceolate to elliptic-oblong, 3.8-17.5 × 2-5.5 cm, at base acute to cuneate, at apex acute to acuminate with tips 3–5 mm, drying papery, adaxially and abaxially densely and rather uniformly puberulous or strigillose to glabrous throughout, with margins plane; secondary veins 10 to 11 pairs, weakly to strongly imiting with each other near margins at least in distal portion of blade, intersecondary veins not or shortly developed, adaxially costa prominent and remaining venation plane or sometimes secondary and loosely reticulated tertiary veins thickened, abaxially costa and secondary veins prominent, loosely reticulated tertiary venation thinly prominulous, and quaternary venation not visible or thickened and densely reticulated. Petioles 5–26 mm, glabrous to densely strigillose. Stipules interpetiolar, persistent at least on distalmost 3 to 5 nodes, ovate to triangular, 4–16 mm, abaxially glabrous to densely puberulous, at apex narrowly acute to acuminate, margins irregularly shortly serrate to shortly laciniate or multifid. Inflorescences axillary, cymose to paniculiform, rounded in outline, 2.5-8 × 2-6 cm (including peduncles), several-(ca. 30) to multiflowered (ca. 90), branched to 1 to 2 orders, with axes cymose, densely strigillose to glabrous, with basalmost secondary axes subtended by ovate foliaceous bracts (or reduced leaves) 0.7-1.6 × 0.8-1.3 cm on stipes (or petioles) 2–5 mm; other bracts stipuliform or narrowly triangular to linear, 0.8–5 mm. Flowers in congested cymes of 5 to 7 and sessile to subsessile or shortly pedicellate on pedicels to 1 mm, with floral biology unknown; hypanthium obconic to ellipsoid, ca. 1 mm, densely strigillose to glabrous. Calyx limb divided nearly to base, glabrous to densely strigillose, lobes 5, narrowly triangular, 2–4 mm, acute. Corolla salverform, violet, externally glabrous, internally glabrous except pilose inside top of tube around anthers, tube ca. 7 mm, ca. 0.6 mm diam, at bottom, ca. 0.8 mm diam. at top, at base irregularly fenestrate with 5 slits, each slit 0.5–1 mm, slits often unequal in size on an individual flower, lobes 5, narrowly triangular, ca. 2 mm, acute and smooth at apex. Stamens 5, inserted below top of corolla tube, anthers ca. 1.2 mm, included and subsessile, color not noted. Stigmas 2, ca. 2 mm, exserted, style ca. 9.5 mm. Capsules and seeds not seen.

Names. — The scientific name created here for this species honors Mr. Charles Rakotovao, collector of the type specimen of this elegant species and one of the Missouri Botanical Garden's resident field botanists. Mr. Rakotovao has extensively documented Madagascar’s flora with excellent specimens collected during numerous explorations made throughout the island. The vernacular name “Vahibivoraka” was noted on the specimen Randriamanarivo & al. 39 and is in the Betsimisaraka dialect. The local name roughly translated into English means “big liana with a soft consistency.” The reference to the soft quality of the plant may indicate that the stems can be compressed by squeezing between the fingers (A. Randrianasolo, pers. comm.).

Habitat and distribution. — This species is documented from humid forests at 720–1098 m in east-central to northeastern Madagascar, in Antsiranana Province (SAVA Region) and Toamasina Province (Analanjirofo and Antsinanana Regions; Fig. 2, humid bioclimatic zone).

Conservation status. — Danais rakotovaoi has an EOO of 711 km², which meets the criterion for Endangered; an AOO of <500 km², which also meets the criterion for Endangered; and three subpopulations. The species is known from three widely separated collections. One of the localities apparently falls just inside the boundaries of a currently protected area (Zahamena National Park), and the northernmost collection was made approximately 3 km outside of the boundaries of a second protected area (Marojejy National Park) and it is quite plausible that the species occurs inside that park as well. The habitat of this species is already significantly fragmented and expected to diminish further in quality. Danais rakotovaoi is assigned a preliminary conservation status of Endangered due to its limited distribution and threatened habitat [EN Blab(i,ii,iii,iv)+2ab(i,ii,iii,iv)].

Notes on morphology, classification and similar species. — Danais rakotovaoi is characterized by its well developed stipules with shortly laciniate margins; its axillary, generally rounded inflorescences; its rather well developed narrow calyx lobes; and its medium-sized violet corollas. The fruits and seeds of this species have not been examined, but all other available features including the climbing habit support the classification of D. rakotovaoi in this genus.

The stipules of this new species are unusual in Danais, and similar only to those of D. antilahimenae; however D. antilahimenae can be separated from D. rakotovaoi by its much larger inflorescences with prolonged spiciform axes, its shorter calyx lobes, and its longer corollas. Only one flowering collection of D. rakotovaoi has been seen, which has flowers that are similar to the long-styled form of distylous species of Danais. This new species is unusual in Danais in the distribution of its leaf pubescence, which is generally uniform in density and trichome size throughout the blade, while in other species of the genus the leaf pubescence is usually denser and composed of longer trichomes on the veins than on the lamina. This new species appears also to be similar to the poorly known species D. coerulea Homolle ex Cavaco based on published descriptions. Danais coerulea is not well characterized but was described as having significantly larger corollas, 20–25 mm long in overall length (i.e., tube plus lobes), vs. ca. 9 mm in overall length in D. rakotovaoi.

Paratypi. — Madagascar. Prov. Toamasina: Analanjiforo, Vavatenina, Miarinarivo, Anamborano, Ambinanini, Sahavarina, à l'interieur de l'AP à 1 km de la limite, 17°41′08″S 48°59′43″E, [no elevation], 16.VI.2001, fl., Randriamanarivo & al. 39 (MO!, TAN); Antsinanana, Brickaville, Maroseranana, Andeka, Amparamanambola, à 6 heures de marches au N d'Andeka, route vers Besaha, 18°24′47″S 48°49′42″E, 720 m, 29.X.2005, bud, Andriamihajarivo & al. 684 (MO!, TAN).

Typus: Madagascar. Prov. Toamasina: Analanjirofo Region, Tampolo (Masoala), Ambanizana, Anjahana, Maroantsetra, 15°44′12″S 49°57′24″E, 200–400 m, 12.X. 2001, fl., Randrianaivo 664 (holo-: MO-6055804! iso-: G [G00369980]).

Haec species a congeneris foliis grandibus late –, stipulis bilobis, lobis calycinis linearibus 1.5–4 mm longis atque corolla satis longa distinguitur.

Woody lianas, climbing to 3 m high; stems glabrous, subterete, with intemodes sometimes prolonged. Leaves opposite; blades elliptic to broadly elliptic or obovate, 9-18.5 × 4.4-13.5 cm, at base obtuse to rounded or truncate, at apex acute or rounded and rather abruptly acuminate with tips 2– 20 mm, drying papery to chartaceous, on both surfaces glabrous and rather shiny, with margins plane to thinly revolute; secondary veins 6 to 8 pairs, free, reticulating, or sometimes looping to interconnect with each other in distal part of blade, adaxially costa prominent and secondary veins and rather densely reticulated tertiary and quaternary venation prominulous, abaxially costa prominent, secondary veins prominulous, and tertiary and quaternary venation plane to prominulous. Petioles 12–35 mm, glabrous. Stipules interpetiolar or shortly united around stem, deciduous after distalmost 1 to 3 nodes, ovate to broadly rounded, 4–6 mm, abaxially glabrous, shortly 2-dentate to 2-lobed for up to 1/2 of length, lobes narrowly to broadly triangular, acute to obtuse. Inflorescences pseudoaxillary (i.e., borne in only 1 axil of a node), produced below stem apex, cymose, rounded to broadly pyramidal in outline, 6-10 × 4-6 cm (including peduncles but not corollas), several- (ca. 15) to multi-flowered (ca. 40), branched to 1 to 2 orders, with axes cymose, densely puberulous to glabrous ; bracts narrowly triangular to linear, 1–3 mm. Flowers in umbelliform to weakly dichotomous cymes of 3 to 7 and all pedicellate on pedicels 0.5– 8 mm, distylous, fragrant; hypanthium ellipsoid to obovoid, 1–2 mm, densely puberulous to glabrous. Calyx limb divided nearly to base, densely puberulous to glabrous, lobes 5, narrowly triangular to linear, 1–2.5 mm and generally equal in length on an individual flower, acute. Corolla salverform, white to yellow, externally glabrous, internally glabrous except pilosulous in throat, tube 14–16 mm, 0.5–1 mm diam. at base, 0.8–1.2 mm diam. at top, at base fenestrate with 5 slits, each slit ca. 1 mm, lobes 5, narrowly triangular to narrowly ligulate, 7–7.5 mm, acute and smooth at apex. Stamens 5, inserted in corolla throat, anthers with color not noted, in long-styled flowers ca. 1.8 mm, partially exserted, and subsessile, in short-styled flowers ca. 2 mm and exserted on filaments 3–4 mm. Stigmas 2, in long-styled flowers ca. 4.5 mm and exserted, with style ca. 16 mm, in short-styled flowers ca. 4 mm and included except tips exserted, with style ca. 10 mm. Capsides oblate, 4-5 × 5-7 mm, subcoriaceous to woody, glabrous, dehiscent for apical 1/3–1/2 of body, beak portion flat. Seeds irregular in shape but generally triangular, ca. 1 mm, with circumferential wing shortly laciniate.

Names. — The scientific name created here for this species honors Mr. Richard Randrianaivo, who collected the type of this handsome species and is one of the Missouri Botanical Garden's resident field botanists. Mr. Randrianaivo has extensively documented Madagascar’s flora with excellent specimens collected during numerous explorations made throughout the island. No vernacular name is noted in the information available.

Habitat and distribution. — Humid forests at 200–400 m in northeastern Madagascar, on the Masoala Peninsula in Toamasina Province (Analanjirofo Region) (Fig. 4, humid bioclimatic zone).

Conservation status. — Danais randrianaivoi has an EOO of 230 km², which meets the criterion for Endangered; an AOO of <500 km², which also meets the criterion for Endangered; and one subpopulation. The species is known only from three localities, one of which is inside the boundaries of a currently protected area (Masoala National Park). The habitat of this species is already significantly fragmented and expected to diminish further in quality. Given the small EOO and its few localities, D. randrianaivoi is assigned a preliminary conservation status of Endangered due to its limited distribution and threatened habitat [EN B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv)].

Notes on morphology and similar species. — Danais randrianaivoi is characterized by its woody rounded stems with generally elongated intemodes; its relatively broad large leaves that are usually shiny on both surfaces; its bidentate stipules that are sometimes shortly united around the stem; its pseudoaxillary cymose inflorescences; its pedicellate flowers; its rather large, white to yellow corollas with very slender tubes and narrow lobes; and its oblate capsules.

The stipules of D. randrianaivoi are variably free to fused across the intrapetiolar portion, with two short, closely arranged, narrowly acute lobes on each interpetiolar side, or sometimes with two broadly triangular obtuse lobes or sometimes apparently entire. The stipules appear to widen markedly with age, as the stem thickens. Puff & Buchner (1994) documented several Danais species with pseudoaxillary inflorescences that are first produced at the stem apex and then displaced or overtopped by subsequent growth from one of the axillary buds, so the flowers are borne at or near the stem apex but the infructescences are left behind as the vegetative part of the stem continues to grow. However in D. randrianaivoi the inflorescences appear to be produced initially in the pseudoaxillary position, well below the stem apex. This new species is similar to D. longipedunculata Homolle, but the latter differs by its elliptic to obovate leaves 3–7 cm wide and its shorter corollas (tubes 5.5–6 mm long and lobes 2–3 mm long).

Paratypi. — Madagascar. Prov. Toamasina: Analanjirofo, Maroantsetra, Anjahana, Ambanizana, 15°42′35″S 49°58′13″E, 200 m, 20.X.2001, fl., Randrianaivo 719 (MO!); Tampolo (Masoala), 15°37′02″S 49°58′46″E, 200 m, 13.IX.2002, fr., Antilahimena & Aridy 1385 (MO!).