Phaseolus ovatus sensu Benth. Comm. Legum. Gen.

Phaseolus ovatus sensu Benth. Comm. Legum. Gen. View in CoL : 77 (1837) in Brazil, pro parte.

Vigna longifolia sensu Du Puy et al. (2002) View in CoL , non (Benth.) Verdc.

Perennial prostrate or climbing vines, foliage and reproductive parts covered with long yellow hairs, with minute glandular hairs intermingled, sparsely or densely pilose. Stems herbaceous, fibrous, often with adventitious roots, sparsely to densely pilose with yellow, straight hairs. Leaves trifoliolate, stipules lanceolate to sagittate, upper extension 4–12 mm long, 2–4 mm wide, membranaceous to chartaceous, 8- to 10-veined, lower portion biauriculate, 1–2 mm long, stipels ovate-lanceolate, shorter than petiolules, ca. 2 mm long, covered with long straight and minute glandular hairs; petioles 2–6 cm long, covered with hirsute, retrorse hairs, rachis considerably shorter, 5–10 mm long, with antrorsely appressed hairs, canaliculate; leaflets entire, ovate, elliptic-ovate, or oblong, usually obtuse or acute at apex, often with raised veins below and the veins outlined in light green relative to the darker green lamina, chartaceous, densely strigose to softly pilose on both surfaces; terminal leaflet 4–6.5 3 2–2.5 cm, lateral leaflets 3–6 3 2–3 cm. Inflorescences 7–13.5 cm long, peduncles up to 13 cm long, covered with straight, retrorse hairs, densely strigose distally, rachis ca. 5 mm long, with 2–3 swollen, ampulliform nodes, ca. 1.5 mm long, with 3–5 vestured orifices, alternately distributed, flowers clustered distally; primary bracts caducous, secondary bracts lanceolate, ca. 10 mm long, caducous; bracteoles mostly persistent at anthesis, lanceolate, 6–10 mm long; pedicels shorter than calyx tube, 3–5 mm long, longer and twisting in fruit, covered with retrorse, straight hairs, antrorse at base of calyx; calyx campanulate, sparsely pilose at base, tube longer than teeth, ca. 3 3 ca. 3 mm, upper teeth emarginate, rounded at apex, not forming a lip, lateral teeth and lower tooth oblong and rounded, ca. 1 mm long. Flowers golden yellow, 1.5–2 cm long, standard petal asymmetric, broadly ovate, ca. 1.5 3 ca. 1.5 cm, bilobed at apex, two parallel, thick callosities on the lamina above the point of folding, two fleshy auricles, 1 mm wide, above a short claw; wing petals longer than keel, with an obovate lamina, 1.5–1.7 3 ca. 1.5 cm, with a prominent auricle at base, claw ca. 3 mm long; keel distinctly beaked, curved through 270, almost forming a complete coil, ca. 1.5 cm above the wing, with transverse pockets above the petal claws, claws ca. 4 mm long, fused to staminal tube; androecium 2 cm long, vexillary stamen with a basal appendage; anthers oblong-ovate, ca. 1 mm long, basifixed to sub-basifixed to their filaments; pollen grains triporate, with a coarsely reticulate exine, interstitium granular; ovary straight, with a basal nectary disc ca. 1 mm long, ovules 10–11 per ovary, style with a tenuous lower part, upper part thickened, cylindrical, curved, pollen brush 4–5 mm long, with long spreading hairs produced beyond the stigma to form a short conical appendage; stigma transversally-ovate, laterally placed. Fruit patent, linear-oblong, flattened, truncate at the apex, valves thin-walled, turning dark brown or black at maturity, densely pilose with yellow hairs, 4.5–6 cm long, ca. 7 mm wide, beak 1 mm long, elastically dehiscent. Seeds (immature) D-shaped, ca. 3 3 ca. 4 mm, surface smooth, testa brown, hilum oblong, ca. 2 mm long, covered by an epihilum, rim-aril raised, aril when present poorly developed, membranaceous and whitish. Chromosome number: 2 n 5 22 (Senff et al. 1992, 1995; Schifino-Wittmann 2000).

Illustrations — Herter (1952) as Phaseolus ovatus ; Isaguirre and Beyhaut (1997) as Vigna longifolia ; Cordazzo and Seeliger (1995) as Vigna luteola ; Snak, Miotto and Goldenberg (2011) as Vigna longifolia .

Distribution and Habitat — Vigna diffusa occurs in southern Brazilian restinga, a coastal low forest or scrub vegetation on sand, along the coast of Rio Grande do Sul, Santa Catarina, and S ~ ao Paulo, south to Uruguay ( Fig. 3 View FIG ). According to herbarium labels, Vigna diffusa was first collected in the nineteenth century on the eastern coast of Madagascar. Three specimens of this species from Madagascar have been found in herbaria, and 1964 was the last time the species was collected on the island. The occurrence in Madagascar is just as likely the result of natural trans-Atlantic dispersal as human introduction because Vigna diffusa occurs on coastal sand dunes, flooded or moist environments, and in grasslands and Restinga communities all at sea level. Flowering and fruiting have been registered in most months except June, and August to November.

Etymology —The species name refers to the spreading habit of the species ( diffusus , spreading).

Vernacular Name —“Feij ~ ao-da-praia” ( Cordazzo and Seeliger 1995).

Representative Specimens Examined —See Appendix 1 for complete list. Brazil. — PARANÁ: Paranagua, Ilha do Mel, 30 Dec 2009, C. Snak et al. 269 (UPCB). Uruguay. — CANELONES: bords de Santa Lucıa, Mar 1867, E. Gilbert 311 (K, W). Madagascar. Sandy dunes near Fort Dauphin, Sep 1890, G. F. Scott Elliot 3023 (BM, K).