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.

PEDIOMELUM

INDIAN BREADROOT

James W. Grimes

Perennial, unarmed, gland-dotted; hairs, stalked glands, or both; roots deep, woody, enlarged near ground surface
Stem: main axis erect, nearly 0 to short; branches short, decumbent to ascending, sometimes underground
Leaves ± palmately compound, ± basal (or cauline at branch tips); stipules at base of plant fused, those above free; leaflets 5–7
Inflorescence: basal, axillary, or terminal on branches, raceme with 1 sometimes tardily deciduous bract and 2–3 flowers per node; pedicel sometimes very short
Flower: calyx base swollen on top, tube enlarging in fruit; corolla at least partly blue to purple; 9 filaments fused, 1 less so or free; ovary ± hairy, ovule 1, style tip curved to bent, stigma head-like
Fruit transversely dehiscent, beaked, hairy, rarely glandular
Seed elliptic, smooth or ridged
Species in genus: 22 species: North America
Etymology: (Greek: plain apple)
Reference: [Grimes 1990 Mem New York Bot Gard 61:1–114]
Bituminaria bituminosa (L.) Stirton (Psoralea b. L.) possibly naturalized in SnBr; Pediomelum mephiticum (S. Watson) Rydb. incorrectly reported for s CA.

Native

P. castoreum (S. Watson) Rydb.

Leaf: stipule 5–13.5 mm; petiole 6.8–15 cm; leaflets 5–6, 25–42 mm, elliptic to oblanceolate
Inflorescence: bract 3.5–8 mm
Flower 9–13 mm; calyx 10–12 mm; banner 9–13 mm
Fruit ovate to elliptic in outline; body 6–8 mm; beak 8–11 mm, straight to curved, triangular
Seed 6 mm, reniform, ridged, gray
Ecology: Open areas, roadcuts
Elevation: < 1750 m.
Bioregional distribution: Mojave Desert (San Bernardino Co.)
Distribution outside California: Nevada, Arizona
Flowering time: Apr–May
Synonyms: Psoralea c. S. Watson
Horticultural information: TRY.