Mucuna jarocha T.M. Moura, V.F. Mansano, R. Gereau & A.M.G. Azevedo, Phytotaxa

De, Tânia M., Lewis, Gwilym P., Mansano, Vidal F. & Tozzi, Ana M. G. A., 2018, A revision of the neotropical Mucuna species (Leguminosae-Papilionoideae), Phytotaxa 337 (1), pp. 448-450 : 448-450

12. Mucuna jarocha T.M. Moura, V.F. Mansano, R. Gereau & A.M.G. Azevedo, Phytotaxa 89(1): 44. 2013 .

TYPE:— MEXICO. Veracruz: município Tlalnelhuayocan, Barranca del Pixquiac , entre Rancho Viejo y La Vega, Elev. 1550 m, 2 August 1986 (fl./fr.), M. Chazaro & J. Caramillo 3386-b (holotype: XAL!) .

Lianas. Leaves 3-foliolate; pulvinus 9.0–12 × ca. 4.0 mm; petiole 9.0– 11 cm long; stipels linear; rachis 1.5–2.0 cm long; petiolules ca. 7.0 mm long; 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, adaxially with both erect and adpressed trichomes, densely sericeous abaxially, venation eucamptodromous, secondary veins in 7–9 pairs. Inflorescence axillary, pseudoracemose; peduncle 20 cm –1.0 m long; rachis 3.0– 5.5 cm long; brachyblasts nodose; internodes 5.0– 10 mm long; bracts 2.0–2.8 × 0.8–1.5 cm, densely sericeous on both surfaces, often caducous; pedicels 3.0– 4.5 cm long. Flower 4.0–5.0 cm long; calyx sericeous on both surfaces, 1.7–2.0 cm long, lobes 4, the adaxial lobe 2.0–3.0 × 6.0–8.0 mm, formed by two entirely connate sepals, apex obtuse, the lateral lobes 4.0–5.0 × ca. 3.0 mm, rounded apically, the abaxial lobe 8.0–9.0 × ca. 5.0 mm, rounded apically; corolla reportedly cream (M. Charazo & J. Camarillo 3886a,b XAL), pinkish (M. Charazo 2698 XAL) or white (M. Rosas 388 BM); standard broadly elliptic, ca. 3.5 × 2.5 cm, basally attenuate, apically rounded, the claw ca. 1.0 mm long, glabrous; wings oblong-obovate, 4.0–4.4 × 1.0– 1.3 cm, basally attenuate, apically obtuse to rounded, pubescent at base, the claw ca. 3.0–4.0 mm long; keel petals oblong, 4.2–4.4 × ca. 1.0 cm, attenuate at base, obtuse at apex, pubescent at base, the claw ca. 1.0 mm long. Stamen filaments ca. 3.7 cm long, glabrous. Gynoecium 4.5–5.0 cm long; ovary ca. 10 × 2.0 mm, densely sericeous; style 3.3–4.0 cm long, sericeous, glabrescent at apex; stigma not seen (because in the few flowers available to our study the stigmas were damaged). Fruit stipitate, conspicuously hispid-pubescent, with long golden brown trichomes; stipe ca. 2.0 cm long; body of fruit ca. 15 × 3.0 cm, oblong in outline, laterally compressed, attenuate at base, acute at apex, the surface not ornamented by lamellae, not constricted between the seeds, lignfied wings along the margin of the fruits; mature seeds not seen.

Taxonomic notes:— Prior to its description, M. jarocha Moura et al. (2013d: 44–46) was often misidentified in herbaria as M. holtonii , especially because of the dense hairs on the abaxial surface of its leaflets, and its nodose brachyblasts; but the two species differ principally by the length of their wing petals. In M. holtonii the wings are shorter than the standard (2.0– 2.3 cm long) vs. in M. jarocha the wings are longer than the standard (4.0– 4.4 cm long). In addition, the inflorescence rachis internodes are longer (5.0– 10 mm long) in M. jarocha than in M. holtonii (2.0–3.0 mm long) and the fruits have lignified wings along their margin (vs lignified wings absent in M. holtonii ).

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

A REVISION OF THE NEOTROPICAL MUCUNA SPECIES

Phytotaxa 337 (1) © 2018 Magnolia Press • 31

Distribution and habitat:— Only a few specimens of Mucuna jarocha were found after a comprehensive search of the main herbaria housing rich collections from South, Central and North America. The species is apparently endemic to Veracruz, Mexico ( Fig. 1 ). It is recorded from an elevation of 1300 m.

Conservation status:— Mucuna jarocha is ranked as Data Deficient (DD) ( Moura et al., 2013d).

Representative specimens examined:— 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 3886a,b ( XAL) ; 5 May 1983 (fl.), M. Chazaro 2698 ( XAL) ; Tonocalco, Zongolica , bosque caducifolio, secundaria, 1150m, 4 March 1976 (fr.), C. Velazquez 27 ( MEXU) ; Tenochtitlán, 2 km en linea recta al SE (115º) de Tenochtitlán, faldas de cerro Quebrado , 8 November 2000 (fl.), A. Rincón & C. Durán 2233 ( MEXU) .

Figures

FIGURE 1. Geographical distribution of six neotropical species of Mucuna: M. chiapaneca and M. jarocha (endemic to Mexico), M. analuciana and M. japira (endemic to Brazil), M. mollis (endemic to Colombia), and M. rostrata (widely distributed in Central and South America, and the Caribbean Islands).