FABACEAE

LEGUME FAMILY

Annual to tree
Leaves generally compound, alternate, stipuled; leaflets generally entire
Inflorescence: generally raceme, spike, umbel or head; flowers sometime 1–2 in axils
Flowers generally bisexual, generally bilateral; hypanthium generally flat or cup-like; sepals generally 5, fused; petals generally 5, free, or the 2 lower ± fused; stamens 1–many, often 10 with 9 filaments at least partly fused, 1 (uppermost) free; pistil 1, ovary superior, generally 1-chambered, ovules 1–many, style, stigma 1
Fruit: legume, sometimes including a stalk-like base above receptacle, dehiscent, or indehiscent and breaking into 1-seeded segments, or indehiscent, 1-seeded, and achene-like
Seeds 1–several, often ± reniform, generally hard, smooth
Genera in family: ± 650 genera, 18,000 species: worldwide; with grasses, requisite in agriculture and most natural ecosystems. Many cultivated, most importantly Arachis , peanut; Glycine , soybean; Phaseolus , beans; Medicago ; Trifolium ; and many orns
Reference: [Polhill & Raven (eds) 1981 Advances in legume systematics; Allen & Allen 1981 Leguminosae]
Family description and key to genera by Duane Isely.

LOTUS

Duane Isely

Annual, perennial herb, shrub, unarmed
Leaves generally odd-1-pinnate (sometimes ± palmately compound, rarely some or most simple); stipules conspicuous or not; leaflets 3–many, often irregularly arranged
Inflorescence: umbel or 1–2-flowered, axillary, generally peduncled, often bracted
Flower: corolla generally yellow (sometimes white or pink), fading darker; 9 filaments fused, 1 free
Fruit dehiscent or not, exserted from calyx or not, ovoid to oblong, ± beaked
Seeds 1–several
Etymology: (Greek: derivation unclear)
Reference: [Isely 1981 Mem New York Bot Garden 25:128–206]
Spp. generally variable; intermediates may be hybrids. Key below separates natural groups.

Native

L. formosissimus Greene

Perennial, ± glabrous, stoloned or rhizomed
Stem sprawling to ascending, often spongy-based, 1–5 dm
Leaf: stipules large, triangular, ± scarious, fragile; leaflets 3–7, ± opposite, 6–20 mm, elliptic or obovate
Inflorescence 3–9-flowered; peduncle bract just below umbel, generally 3-parted
Flower: calyx 5–6 mm, lobes ± = or < tube; corolla 10–16 mm, banner yellow, wings pink-purple, fading white, claws exserted from calyx tube
Fruit dehiscent, 2–3 cm, 2–3 mm wide, oblong
Seeds few
Ecology: In water or springy areas, shores, meadows, roadside ditches
Elevation: < 650 m.
Bioregional distribution: North Coast, Outer North Coast Ranges, n Central Coast, San Francisco Bay Area, n Outer South Coast Ranges
Horticultural information: IRR, SUN: 15, 16, 17.