Vines 2–5 m. Stems often intri­cately twining, usually softly pilose, rarely glabrous. Leaves: stipules triangular-ovate, 3–4 mm; petiole 2.5–8 cm; rachis 0.4–1(–1.7) cm; stipels thin, linear or broader, 0.5–1.5 mm; leaflets membranous, blades ovate, 4–11 × 2–6 cm, base cuneate to truncate, apex acuminate, surfaces usually densely pale-pubescent abaxially. Inflorescences 5–30 cm, flow­ers clustered at 2 or 3 nodes; primary bracts caducous. Pedicels 3–4 mm; bracteoles 2.5–4 mm. Flowers light purple to deep-lilac, 3–4 cm; calyx 8.5–10 mm, glabrous or sparsely pubescent, lower and lateral lobes triangular, 4–4.5 × 3 mm, upper lobes rounded, 7–11 mm wide; banner oblong to suborbiculate, 3–3.5 × 2.5–3 cm; wings obliquely obovate, 3.5–4 × 1.5–1.8 cm; keel beak abruptly curved and sigmoid; vexillary stamen geniculate distal to base. Legumes narrowly linear, 10–18 × 0.4–0.7 cm, thinly strigose. Seeds 1–20, reniform or oblong, 4.5–5 × 2.3–3 mm.

Phenology: Flowering May–Jan.
Habitat: Pinelands, roadsides, vacant lots.
Elevation: 0–20 m.

Distribution

• Generated Map
• Legacy Map

Introduced; Fla., Mexico, Central America, South America.

Discussion

Sigmoidotropis speciosa is used as an ornamental; it is established in central peninsular Florida (R. P. Wunderlin and B. F. Hansen, http://florida.plantatlas.esf.edu/) and been listed as a Category II invasive species by the Florida Exotic Pest Plant Council (www.fleppc.org). It has frequently been confused with another ornamental vine, Cochliasanthus caracalla (Linnaeus) Trew (corkscrew flower), that has showy white-yellow or light lavender corollas with keel petals that loosely coil several turns.

Selected References

None.

Lower Taxa

None.