Lablab purpureus

Herbs climbing or bushy-erect, 1–6 m. Leaves: stipules reflexed in age, ovate-triangular, 4–6 × 1 mm; petiole 1–18 cm, strigose, ± glabrescent; rachis 0.7–4.5 cm; stipels linear lanceolate, 2 mm; leaflet blades ovate-triangular, 2–15 × 1.5–14 cm, base cuneate to truncate, apex acute to acuminate. Peduncles 2–40 cm. Inflorescences: bracts often deciduous, ovate-lanceolate, 4 mm. Pedicels 2–3.5 mm, shorter than calyx tube; bracteoles 4–6 × 1–4.5 mm, appressed to calyx. Flowers: calyx 3–6 mm, glabrous or strigose, tube longer than lobes, 2 upper lobes connate, lower and lateral lobes triangular or linear-oblong, 2–4 mm; corolla banner reflexed, with 2 prominent appendages on base of inner-face lamina, base auriculate, apex emarginate; wings oblong, longer than keel, auriculate; keel beak purple-tipped, incurved at right angle; vexillary stamen with gibbous appendage at base, filaments alternately long and short; ovary glabrous or pubescent, often with minute tubercular hairs. Legumes 5–10 × 1.5–40 cm. Seeds compressed, 9–13 × 6.5–9 mm. 2n = 22 or 24.

Phenology: Flowering summer–fall.
Habitat: Waste areas, roadsides, railroads.
Elevation: 0–300 m.

Introduced; D.C., Fla., Ga., Md., N.J., N.Y., Ohio, Pa., Va., W.Va., e Africa, introduced nearly worldwide.

Discussion

Lablab purpureus is widely cultivated in warm temperate to tropical climates for human food and livestock fodder, green cover, and medicine, and as an ornamental (http://plants.usda.gov/plantguide/pdf/pg_lapu6.pdf). A historical record from Ontario should be treated as a waif.

Selected References

None.

Lower Taxa