Mucuna mitis (Ruiz & Pav.) DC., Prodr.

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

15. Mucuna mitis (Ruiz & Pav.) DC., Prodr. 2: 405. 1825. ( Fig. 17 )

Negretia mitis Ruiz & Pav., Syst. Veg. Fl. Peruv. Chil. 177. 1798. TYPE:— PERU. Chinchão. Herbário de Ruiz & Pavon s.n. [lectotype: MA! 812451, designated by Moura et al. 2013e].

Mucuna mapirensis (Rusby) J.F. Macbr., Publ. Field Mus. Nat. Hist., Bot. Ser. 13(3/1), pt. 3: 315. 1943. Stizolobium mapirense Rusby, Mem. Torrey Bot. Club 6(1): 25. 1896. TYPE:— BOLIVIA. Between Guanai and Tipuani, June–July, 1802 (fl.), A.M. Bang 1413 (possible isotypes: BM!; K!; LE!; US!; W!).

Liana. Leaves 3-foliolate; pulvinus 10–15 × 3.0–4.0 mm; petiole 9.0– 10 cm long; stipels absent; rachis 2.0– 2.5 cm long; petiolule 5.0–7.0 mm long; lateral leaflets, 11–14 × 6.0–7.0 cm, asymmetric at base, acuminate to caudate at apex; apical leaflet elliptic, 12–13 × 6.0–7.0 cm, rounded at base, acuminate to caudate at apex; venation eucamptodromous, secondary veins 4–6 pairs per leaflet; dense erect hairs on the abaxial surface of leaflets. Inflorescence axillary, pseudoracemose; peduncle ca. 1.0 m long; bracts not seen; pedicels 2.5–5.0 cm long, 7.0–12 nodes per inflorescence, 3 flowers per fleshy node, the nodes 5.0– 12 mm apart, distichously arranged, sometimes in a “zig-zag” (fractiflex) pattern. Flowers 5.0–6.0 cm long; calyx 2.0– 2.5 cm long, 4-lobed, the adaxial lobe formed by two connate sepals, ca. 5.0 × 10 mm, obtuse at apex; the abaxial lobe ca. 10 × 6.0 mm, acute at apex; lateral lobes 6.0–10 × 5.0 mm, rounded to slightly acute at apex; corolla reported to be green (W. Palacios 2991 QCNE), greenish (W. Palacios 4239 QCNE) or yellowish-green (R.B. Foster 9383 MO); standard broadly elliptic, 4.5–5.0 × 2.2–2.9 cm, attenuate at base, rounded at apex, the claw ca. 10 mm long; wings oblong-elliptic, 4.5–6.0 × 1.1–1.4 cm, attenuate at base; obtuse at apex, the claw ca. 15 mm long; keel petals oblong, 2.5–6.0 × 2.0– 2.4 cm, attenuate at base, obtuse at apex, the claw ca. 10 mm long; wing and keel petals pubescent at base. Stamen filaments 4.0–5.0 cm long, glabrous. Gynoecium 5.0–6.0 cm long; style 3.5–5.0 cm long, sericeous except at apex; ovary oblong, 10–13 × 2.0 mm, sericeous. Fruits 14.5–24 × 2.0–4.0 cm, ornamented with obscure transverse lamellae, stipitate, stipe ca. 2.0 cm long, attenuate at base; caudate at apex; with an indumentum of dense hairs when young, the hairs lost at maturity, 2–6-seeded. Seeds globose, 2.5 × 2.5 × 1.0 cm; hilum black, circling ca. 80% of the seed circumference.

Taxonomic notes:— Mucuna urens is the species most morphologically similar to M. mitis ( Ruiz & Pavon 1798: 177) De Candolle (1825: 405) . These are the only two species in the Neotropics with the rachis of their inflorescences in a ‘zig-zag’ (fractiflex) pattern. Nevertheless, M. mitis differs by its dense erect hairs on the abaxial surface of the leaflets, and the 3–5 cm long pedicels (vs. sparse adpressed hairs on the abaxial surface of the leaflets, and the pedicels 0.7–2.0 cm long in M. urens ).

Phenology:— Flowering March to October; fruiting April to December.

Distribution and habitat:— Mucuna mitis occurs in Bolivia, Ecuador and Peru ( Fig. 5 ). It grows in primary and transition wet forest and in pre-montane forest, between 200 and 1420 m.

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Conservation status:— Mucuna mitis is as assessed as being of Least Concern (LC). Although M. mitis has a restricted area of occupancy (84 km 2, EN), the habitat in which it occurs is not considered to be significantly fragmented, and the species has been collected from more than ten localities. No recent decline, or fluctuation, in known populations has been recorded.

Vernacular names: — ‘ Pepa redonda’, ‘huasca’, ‘ojo de baca’ [ Ecuador (C.E. Cerón 20784 K, MO, QCNE; C.E. Cerón 19010 QAP)].

Representative specimens examined:— BOLIVIA. Florida: Parque Nacional Amboro, La Playa, 15–20 km N de Rosa de Lima, Ribera del Rio Agua dulce y juntas com el Rio Moija , 7 April 1993 (fr.), I.G. Vargas et al. 2172 ( MO) . Guanai: Tipuani , 1802 (fl.), A.M. Bang 1413 ( BM, E, K, US, W) ; Guanay, Tipuani , April 1892 (fl.), A.M. Bang 1412 (K) . ECUADOR. Esmeraldas: Quininde, Bilsa biologica reserve. Marçoe mountains , 35km W of Quinindé , 5 km W of Santa Isabel, Main road between la Y de la laguna and station, premontane wet forest, 14 October 1994 (fl.), J.L. Clark & B. Adnepos 192 (K) . Morona-Santiago: Taisha, Rio Guambine , riverside forest, 19 June 1980 (fl.), J. Brandbyge & E. Asanza 32093 ( AAU) . Napo: Margen derecho del Rio Napo, 8 km de Puerto Misahualli , September 1988 (fr.), W. Palacios 2991 ( QCNE) ; Canton Tena, Estación Biológica Jatun Sasha, Rio Napo, 8 Km al E de Misahualli, 18 May 1989 (fl.), W. Palacios 4239 ( QCNE) ; Reserva Biológica Jatum Sacha , 8 km de Puerto Misa, 4 September 1987 (fr.), C.E. Cerón 1973 ( MO, QCNE) ; Reserva Biológica Jatum Sacha , parcela permanente 05, 5 June 1992 (str), C.E. Cerón 19010 ( QAP) ; Chonta Punta et Rio Napo, in the vicinity of Santa Rosa , 5 May 1972 (fl.), H. Lugo 2122 ( GB, MO) . Pastaza: Rio Curaray , Costado S, alrededores de la Laguna Garzayacu, bosque humedo tropical, August 2012 (fl.), D. Neill & W. Palacios 6738 ( MO, QCNE) ; at puento Santana , 20 km along rives Pastaza, SE of Shell Mera, 1968 (fl.), L. Holm-Nielsen & S. Jeppesen 516 ( AAU) . Sucumbios: Gonzalo Pizarro , bosque humedo premontano, 2 December 1992 (fr.), C.E.Cerón 20784 (K, MO, QCNE) . Zamora-Chinchipe: El Pangui Cantón, Región de la Cordillera del Cóndor, Valle del Rio Quimi , bosque húmedo premontano, 17 May 2008 (fr.), W. Quizhpe & R. Steeves 3081 ( MO) . PERU. Amazonas: Rio Cenepa, vicinity of Huampami , cerca de Huampami , 12 August 1978 (fr.), A. Kujikat 297 ( MO) . Bagua: Imaza, region Nororiental del Maraño , 9 August 1994 (fl.), N. Jaramillo et al. 345 ( MO) ; Imaza, Kampaensa, Bosque Rivera , 21 October 1995 (fr.), R. Vázquez et al. 20378 (K, MO) ; Imaza, Região nororiental de Marañon. Comunidade de YaMaio , Bosque de transição, 9 August 1994 (fr.), N. Jaramillo et al. 335 (K, MO) . Chinchão: Mapanauhi , without date (fl.), H. Ruiz & J.A. Pavón s.n. ( MA) . Huanuco: Pachitea, Codo de Pozuzo , alluvial fan floodplain, 22 October 1982 (fl.), R.B. Foster 9383 ( MO) . Pozuzo: Llamapañaquin , without date, H. Ruiz & J.A. Pavón s.n. ( MA) . San Martín: Mariscal Caceres, Tocache Nuevo, Old trail to Limón N of tocache Nuevo near granja Santa Inés , 2 July 1978 (fr.), T. Plowman & J. Schunke 7550 (K); Mariscal Cáceres , Tocache Nuevo , quebrada de Huaquisha (margen derecha del rio Hullaga ), 12 May 2012 (fl.), J. Schunke 3969 ( MO) . Ucayali: Coronel Portillo, Cuenca del Rio Iparia, afluente de rio Uacayali , bosque primario al borde de la quebrada, 8 June 2007 (fr.), J.G. Graham & J.S. Vigo 4562 (K) .

Figures

FIGURE 5. Geographical distribution of four neotropical species of Mucuna: M. argyrophylla (Mexico and Central America), M. mitis (endemic to South America); and M. holtonii and M. mutisiana (distributed from Mexico to NW South America, the latter also occurring in the Dominican Republic).

FIGURE 17. Mucuna mitis. A—Leaves and inflorescence in bud. B—Detail of hairs on the abaxial surface of leaflets. C—Androecium (9 stamens united into a staminal sheath, here opened out, and a single free vexillary stamen). D—Gynoecium. E—Standard. F—Keel petals. G—Wing. H–Calyx opened out, outer surface. J—Young fruits. A—B drawn from: R.B. Foster 9383 (MO); C–H: H. Lugo 2122 (MO); J: C.E. Cerón 1973 (MO). Drawn by Ana Lúcia Souza.