Chodat, Bull. Herb. Boissier 3:545. 1895
Scandent shrub or liana; stems bearing raised, round, stipular glands at the junction of each petiole; most parts softly short-pilose. Petioles 2-4 mm long; blades oblong-ovate to ovate, obtuse to rounded and sometimes emarginate at apex, rounded to truncate at base, 3.5-9.5 cm long, 2-3.5 (4) cm wide, sparsely pilose or glabrate above, densely velvety-pilose below. Racemes terminal, 3-3.5 cm long; pedicels 5-8 mm long; flowers magenta, to 1 cm long; outer sepals 2, enlarged, 3.5-5 mm long, the other 3 oval, 2.5-4 mm long; petals 3, the upper 2 obovate or obovate-spatulate, 8-11 mm long, the lower 1 keeled, enclosing sexual parts, folded, with a minute fimbriate crest at apex less than 1 mm long; stamens 8, united at base into a sheath, pubescent at base; anthers much shorter than stigma; style 7.5-11 mm long; stigma bilobed. Samaras 4.5-7 cm long, densely short-pilose at least on seminiferous part; wing obovate-oblong, 4-6 cm long, 1-2 cm wide, with a small stipitate gland on margin near seed; seed apical, 5-8 mm long. Woodworth & Vestal 505.
Not seen in recent years; rare or no longer present on the island. The species apparently flowers more than once per year, mostly in May and June (rarely early July), with the fruits maturing in July and August, and again in September, with the fruits maturing in January.
Woodworth & Vestal 505 was collected in flower in February. It is intermediate in several ways between S. tenuifolia and S. diversifolia and may represent only an aberrant collection of the latter species.
Panama; Trinidad. In Panama, known from tropical moist forest in the Canal Zone, Veraguas, Panama, and Darien and from premontane wet forest in Colon (Santa Rita Ridge).