Flora of Barro Colorado Island

Vigna vexillata

(L.) A. Rich. in Sagra, Hist. Cuba 10:191.1845

Twining herbaceous vine; stems and petioles conspicu­ously brownish-pilose. Leaves trifoliolate; stipules nar­rowly lanceolate, 4-7 mm long, sagittate at base, the lobes to 1 mm long; petioles 1.5-4 cm long; rachis 5-15 mm long; leaflets generally oblong-lanceolate, usually nar­rowly acute at apex, obtuse to truncate at base, 2.5-11 cm long, 1.5-5 cm wide, ± strigillose above and below, the lateral leaflets oblique. Racemes bearing few flowers; peduncles 5-18 cm long, with stout, brown, retrorse trichomes near apex; pedicels opposite, in 1 or 2 pairs; calyx to 12 mm long, the lobes ± equal, the lowermost lobe longest; petals white to blue when opening in the morning with yellow spots on either side of the standard at base, becoming pale yellow through the course of the day, then falling; standard to 2.5 cm long and 3.7 cm wide, emarginate at apex; wings free, ca 1.5 cm wide, the keel petals free to about the middle, enveloping the sta­mens and very much twisted to one side; style protruding from the tube formed by the outer part of the keel petals, ca 8 mm longer than stamens, the trichomes fine, retrorse, villous, near the apex. Legumes linear, narrowly acute at apex, 7-10 cm long, ca 5 mm wide, dark brown, pilose; seeds many, oblong, to 5 mm long, dark brown, with a white hilum. Croat 5625.

Infrequent, in small clearings and along the shore. Apparently flowers throughout the year, more abundantly during the rainy season. Though flowers are produced every day, few fruits are set-those seen were mature in the early dry season.

Standley (1933) reported Vigna repens (L.) O. Kuntze on the basis of a misidentified collection of Phaseolus trichocarpus.

Pantropical. In Panama, known from tropical moist forest in the Canal Zone, Bocas del Toro, Panama, and Darien and from premontane wet forest in Bocas del Toro.

See Fig. 294.