Mucuna jarocha T. M. Moura, Mansano, Gereau & A. M. G. Azevedo, 2013

Moura, Tânia M., Mansano, Vidal F., Gereau, Roy & Tozzi, Ana Maria G. A., 2013, Mucuna jarocha (Leguminosae-Papilionoideae-Phaseoleae), a new species from Mexico, Phytotaxa 89 (1), pp. 43-46 : 44-46

Mucuna jarocha T. M. Moura, Mansano, Gereau & A. M. G. Azevedo , sp. nov. ( Fig. 1 )

Haec species Mucunae holtonii (Kuntze) Moldenke similis, sed ab ea corolla alis 4–4.4 cm (vs. 2–2.3 cm) longis quam vexillo longioribus praecipue differt.

This new species is similar to Mucuna holtonii (Kuntze) Moldenke , but it differs principally by the length of the wing petals; in M. holtonii the wings are shorter than the standard (2–2.3 cm long) and in M. jarocha the wings are longer than the standard (4–4.4 cm long).

Type:— MEXICO. Veracruz: municipio Tlalnelhuayocan, Barranca del Pixquiac , entre Rancho Viejo y La Vega, 1550 m, 02 August 1986 (fl, fr), M . Chazaro & J . Caramillo 3386-b (holotype XAL!) .

Lianas; young branches pubescent. Leaves with stipules ca. 8 × 1 mm, triangular, sericeous; pulvinus cylindrical, 0.9–1.2 × ca. 0.4 cm, pubescent; petiole 9–11 cm long, pubescent; rachis 1.5–2 cm long, pubescent; stipels linear, ca. 0.7 cm long, sericeous; petiolules ca. 0.7 cm long, pubescent; blades ovate to elliptic, that of apical leaflet 11.5–14 × 8.5–11.5 cm, obtuse to rounded at base, those of lateral leaflets 10.5–15 × 8.5–10.5 cm, asymmetrical, rounded to cordate at base, all blades acuminate at apex (acumen 1–1.5 cm long), adaxially with both erect and adpressed trichomes, densely sericeous abaxially, venation eucamptodromous, secondary veins in 7 to 9 pairs. Inflorescence axillary, pseudoracemose, pendent, with 20 to 30 flowers; peduncle 0.2–1 m long, pubescent; axis 3–5.5 cm long, densely pubescent, the secondary axes nodose, the nodes spirally arranged, the internodes 0.5–1 cm long; bracts caducous; pedicels 3–4.5 cm long, 3-fasciculate at each node, densely pubescent; bracteoles 2–2.8 × 0.8–1.5 cm, densely sericeous on both surfaces. Flower 4–5 cm long; calyx campanulate, with long appressed trichomes on both surfaces, 1.7–2 cm long, lobes 4, the adaxial lobe 0.2–0.3 × 0.6–0.8 cm, formed by two entirely connate sepals, apex obtuse, the lateral lobes 0.4–0.5 × ca. 0.3 cm, rounded apically, the abaxial lobe 0.8–0.9 × ca. 0.5 cm, rounded apically; corolla pentamerous, reportedly cream (M. Charazo & J. Camarillo 3886, XAL), pinkish (M. Charazo 2698, XAL) or white (M. Rosas 388, BM); standard ca. 3.5 × 2.5 cm, broadly elliptic, basally attenuate, apically rounded, the claw ca. 0.1 cm long, glabrous; wing petals 4–4.4 × 1–1.3 cm, oblong-obovate, basally attenuate, apically obtuse to rounded, pubescent at base, the claw ca. 0.3–0.4 cm; keel petals 4.2–4.4 × ca. 1 cm, oblong, attenuate at base, obtuse at apex, pubescent at base, the claw ca. 0.1 cm; nine stamens fused for basal 65–70% of filament length, one free; filaments ca. 3.7 cm long, glabrous; only basifixed anthers observed, these 0.2–0.4 cm long; gynoecium 4.5–5 cm long; ovary sessile, oblong in outline, ca. 1 × 0.2 cm, densely sericeous, 2- to 5-ovulate; style 3.3–4 cm long, sericeous, glabrescent at apex; stigma not seen. Fruit indehiscent, woody, stipitate, conspicuously hispid-pubescent, with long golden brown trichomes; stipe ca. 2 cm long; body ca. 12 × 2.5 cm, oblong in outline, laterally compressed, attenuate at base, acute at apex, the surface not ornamented by lamellae, not constricted between the seeds (only young fruit seen); seeds not seen.

Distribution and ecology: —Only a few specimens of Mucuna jarocha were found after a comprehensive analysis of specimens from several herbaria with rich collections from South, Central and North America. It seems be an endemic species to Veracruz, Mexico ( Fig. 2 ), occurring at elevations above 1300 m.

Phenology: —Flowering May to August and fruiting in August.

Etymology: —The species is named in honor of the residents of Veracruz, known as “Jarochos/as”. The specific epithet is intended as a noun in apposition.

Conservation status: —According to the IUCN criteria ( IUCN 2001), we consider this species as Data Deficient (DD), because we do not have adequate information to make the conservation assessment of Mucuna jarocha .

Additional specimens examined (paratypes): — MEXICO. Veracruz: Camino de Rincón Grande- Atzacan 51-B-1, 1350 m, 15 May 1967 (fl), M . Rosas 388 ( BM, P); Tlalnelhuayocan, Barranca del Pixquiac , entre Rancho Viejo y La Vega, 1550 m, 2 August 1986 (fl), M . Charazo & J . Caramillo 3886-a ( XAL); 5 May 1983 (fl), M . Chazaro 2698 ( XAL) .

Discussion: — Mucuna jarocha is commonly determined as M. holtonii . The confusion might be due to the fact that both species have leaflets with their abaxial surface densely pubescent and long peduncles with nodose secondary inflorescence axes. However, these two species are different, principally because in M. holtonii the wing petals are shorter than the standard (2–2.3 cm long), whilst in M. jarocha the wings petals are longer than the standard (4–4.4 cm long).

Figures

FIGURE 1. Mucuna jarocha. A: Branch with a leaf and an inflorescence; B: detail of abaxial leaflet surface; C: outer face of the opened calyx; D: standard petal; E: wing petals; F: keel petals; G: androecium (9+1 filaments); H: gynoecium; J: immature fruit. Drawn by Tânia Maria de Moura. Voucher: M. Chazaro & J. Caramillo 3386-b (XAL).

FIGURE 2. Geographical distribution map of Mucuna jarocha. Created using BRAHMS 6.9 via Diva GIS.