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.

LATHYRUS

WILD PEA

Duane Isely

Annual or perennial herb, unarmed, glabrous or hairy, rarely glandular, generally rhizomed
Stem sprawling, climbing, or erect; stem angled, flanged, or winged
Leaves even-1-pinnate; stipules persistent, upper lobe > lower; main axis ending as a tendril or short bristle; leaflets 0–16, ± opposite or alternate, linear to widely ovate
Inflorescence: raceme, generally axillary, 1–many-flowered
Flower: upper calyx lobes generally < and wider than lower; corolla 8–30 mm, pink-purple or pale, sometimes white or yellow; 9 filaments fused, 1 free; style flat, finely hairy on concave side
Fruit dehiscent, oblong, ± flat
Species in genus: ± 150 species: temp North America, Eurasia
Etymology: (Ancient Greek name)
Reference: [Broich 1987 Syst Bot 12:139–153]
Some species variable, intergrading with others; some hybridization probable. Seeds of most alien species. TOXIC to humans (especially young males) and livestock (especially horses).

Native

L. vestitus Nutt.

Perennial, glabrous or puberulent
Stem often sharply angled or flanged
Leaf: stipules small and entire to wide and wavy-margined; leaflets 8–12, 2–4.5 cm, linear to elliptic; tendril branched, coiled
Inflorescence 8–15-flowered, often dense
Flower: calyx tube < or > lower lobes, which in some phases may be slightly wider above base; corolla 14–20 mm, generally purple or lavender, sometimes white; banner bent or reflexed ± 90° or more
Fruit glabrous or initially puberulent
Chromosomes: 2n=14
Ecology: Chaparral, oak woodland, coniferous or mixed forest
Elevation: < 1500 m.
Bioregional distribution: North Coast, Klamath Ranges, North Coast Ranges, Central Western California, Southwestern California.Intergrading complex of taxa and local variants (see Broich).

Native

var. vestitus

Plant glabrous or puberulent
Flower: corolla 14–18 mm, pale lavender to purple, banner bent ± 90°
Ecology: Coniferous forest in n to chaparral and oak woodland in s
Elevation: < 1500 m.
Bioregional distribution: North Coast, North Coast Ranges, Central Western California, Southwestern California
Synonyms: subsp. bolanderi (S. Watson) C.L. Hitchc., in part; subsp. puberulus (Greene) C.L. Hitchc.; L. laetiflorus Greene, including subsp. barbarae (T.G. White) C.L. Hitchc
Variable: see Broich for more detailed classification. May hybridize with L. jepsonii var. californicus
Horticultural information: 16, 17, SHD: 15 &IRR: 7, 9, 14; INV; STBL.