Common Name: LEGUME FAMILY
Habit: Annual to tree. Leaf: generally alternate, generally compound, generally stipuled, generally entire, pinnately veined Inflorescence: generally raceme, spike, umbel or head; or flowers 1--few in axils. Flower: generally bisexual, generally bilateral; hypanthium 0 or flat to tubular; sepals generally 5, generally fused; petals generally 5, free, fused, or lower 2 +- united into keel (see 3, Key to Groups, for banner, wings); stamens 10 or many (or , 5, 6, 7, 9), free or fused or 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, including a stalk-like base (above receptacle) or not. Seed: 1--many, often +- reniform, generally hard, smooth.
Genera In Family: +- 730 genera, 19400 species: worldwide; with grasses, requisite in agriculture, most natural ecosystems. Many cultivated, most importantly Arachis, peanut; Glycine, soybean; Phaseolus, beans; Medicago, alfalfa; Trifolium, clovers; many orns. Note: Unless stated otherwise, fruit length including stalk-like base, number of 2° leaflets is per 1° leaflet. Upper suture of fruit adaxial, lower abaxial. Anthyllis vulneraria L. evidently a waif, a contaminant of legume seed from Europe. Laburnum anagyroides Medik., collected on Mount St. Helena in 1987, may be naturalized. Ceratonia siliqua L., carob tree (Group 2), differs from Gleditsia triacanthos L. in having evergreen (vs deciduous) leaves that are 1-pinnate (vs 1-pinnate on spurs on old stems, 2-pinnate on new stems) with 2--5(8) (vs 7--17) 1° leaflets, commonly cultivated, now naturalized in southern California. Aeschynomene rudis Benth. , Halimodendron halodendron (Pall.) Voss (possibly extirpated), Lens culinaris Medik. are agricultural weeds. Caragana arborescens Lam. only cult. Ononis alopecuroides L. , Sphaerophysa salsula (Pall.) DC. all evidently extirpated. Cercidium moved to Parkinsonia; Chamaecytisus to Cytisus; Psoralidium lanceolatum to Ladeania.
eFlora Treatment Author: Martin F. Wojciechowski, except as noted
Scientific Editor: Martin F. Wojciechowski, Thomas J. Rosatti.
Common Name: PALO VERDE
Habit: Tree, shrub, with stipular spines at nodes or thorns in leaf axis (see leaf scars) or main leaf axis a strong spine. Stem: +- zigzag; bark smooth, green. Leaf: alternate or in clusters of 1--6 in spine axils, generally even-2-pinnate, sometimes appearing 1-pinnate, main axis flat, leaflets alternate, falling early or not; 1° leaflets 2--6; 2° leaflets 4--many. Inflorescence: raceme, axillary, generally < 7-flowered. Flower: +- bilateral; sepals +- free, alike, generally reflexed; petals +- equal, generally yellow or cream-white; stamens 10, yellow to orange, free, exserted. Fruit: indehiscent to partly late-dehiscent, generally flat, oblong, +- inflated, narrowed between seeds or not. Seed: 1--several.
Species In Genus: 11--12 species, 2 named hybrids: America, southern United States to Argentina, Africa; cultivated. Etymology: (J. Parkinson, London, apothecary, author, 1567--1650) Note: Haston et al., Hawkins support treatment of Cercidium and Parkinsonia, both recognized in TJM (1993), as single, monophyletic genus.
Unabridged Note: Since S. Watson (1870s), Cercidium and Parkinsonia have variously been treated as 1 or 2 genera; Carter 1974 and McClintock in TJM (1993) recognized both genera but work of Hawkins 1996 (Ph.D. Dissertation, Univ. Oxford, UK) and Haston et al. 2005 (Amer J Bot 92:1359--1371) support treatment as 1 monophyletic group.