Abrus precatorius
Syst. Nat. ed. 12, 2: 472. 1767.
Stems to 50 cm. Leaves 4–10 cm; stipules caducous, linear, 5 × 1 mm; pinna blade oblong to elliptic, 5–30 × 3–10 mm, base obtuse, apex obtuse, usually terminated by bristle, surfaces sparsely pubescent abaxially, hairs appressed, minute, glabrous adaxially. Racemes shorter than leaves. Flowers: calyx subactinomorphic, 2–4 mm, sparsely pubescent; corolla 9–12 mm, glabrous. Legumes (2–)3–4(–5) × 1–1.5 cm, smooth or muriculate; 2-valved, lightly septate. Seeds usually red with black spot surrounding hilum, sometimes black throughout, black and white, or whitish, 5–7 × 4–5 mm, lustrous; hilum eccentric, elliptic, to 1 mm diam. 2n = 22.
Phenology: Flowering Jun–Nov.
Habitat: Borders of woods, hedges, fields, waste places.
Elevation: 0–10 m.
Distribution
Introduced; Fla., s, se Asia, Africa, introduced also in Mexico, West Indies, Central America, South America, elsewhere in Asia, Indian Ocean Islands, Pacific Islands, Australia.
Discussion
B. Verdcourt (1970) pointed out that there are two entities, or subspecies, of Abrus precatorius: the typical subspecies, with smooth fruit surfaces, from Sri Lanka, India, and southeast Asia; and subsp. africanus Verdcourt from Africa, with muriculate fruit surfaces covered with low tubercles. There appear to be separate introductions to Florida, perhaps by way of the West Indies, as both subspecies and intermediates are to be found. Distinction of the two subspecies in the flora area is problematic.
The seeds are poisonous and importation of the species is prohibited in Canada (Canadian Food Inspection Agency, http://www.inspection.gc.ca/english/plaveg/oper/prohibintere.shtml). They have been used historically as standard weights in East Asia and are commonly used for rosaries and novelty jewelry (O. N. Allen and E. K. Allen 1981); this use is now prohibited in the United States (R. C. Dart 2004).
Selected References
None.