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.

ACACIA

Elizabeth McClintock

Tree, shrub, armed or unarmed
Leaves even-2-pinnate or, if simple, true blades 0, petioles and midribs blade-like (comprising phyllodia), generally alternate, generally evergreen; axes with prominent raised glands or not
Inflorescence: heads, spheric, generally axillary, these solitary or in racemes or panicles, or flowers in spikes
Flower radial; sepals, petals inconspicuous; stamens many, conspicuous, exserted, free
Fruit generally dehiscent, sometimes tardily so, flat or ± cylindric
Species in genus: ± 1200 species: tropical, subtropical, especially Australia
Etymology: (Greek: sharp point)
Reference: [Whibley 1980 Acacias of South Australia; Clarke et al. 1989 Systematic Botany 14:549–564]
Australian species cultivated, sometimes naturalized and spreading in CA (seed arilled, stalk often elongated, encircing seed or not).

Native

A. greggii A. Gray

CATCLAW

Shrub, small tree 2.5–7 m, with curved prickles on stem
Stem: twig ± angled, hairy
Leaves 2-pinnate, alternate, clustered on short-shoots or not, deciduous, gray-green; 1° leaflets 2–3 pairs, separated, 1–1.5 cm; 2° leaflets < 10 pairs, ± overlapped, < 6 mm, oblong
Inflorescence: spikes 1 or more, clustered with leaves on short-shoots, generally > leaf
Flower light yellow
Fruit 5–15 cm, recurved or twisted, flat, narrowed between seeds, glaucous, brown
Seed: stalk 0
Ecology: Uncommon. Flats, washes
Elevation: 100–1400 m.
Bioregional distribution: Desert
Distribution outside California: to Texas, Mexico
Flowering time: Apr–Jun
Horticultural information: SUN, DRN: 7, 8, 9, 10, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 &IRR: 11, 13.