Flora of North America species comparison

erect to ascending or pendulous, glabrous or pubescent;

twigs not flexuous or slightly so, terete to angled or ridged, short shoots usually absent.

phyllodic;

phyllode flat, not falcate, narrowly elliptic, 50–150 × 10–25 mm, venation parallel, with 2–4 prominent veins, minor veins prominent, apex acute to obtuse, apiculate, surfaces glabrous;

gland 1, 0–7 mm distal to pulvinus;

pulvinus 2–5 mm.

alternate (except fascicled or whorled in A. verticillata), even-bipinnate or phyllodic, leaves often modified (in age) to polymorphic phyllodes (enlarged, flattened petiole without leaflets), usually glandular on margins and/or apex, saplings often with even-pinnate juvenile leaves often not present at maturity;

stipules usually present, usually early deciduous, rarely woody, spinose; petiolate, usually with 1 globose gland;

pinnae [1 or] 2–31[–50] pairs, mostly opposite;

leaflets 8–70 pairs per pinna, opposite, sessile or subsessile, blade margins entire, surfaces glabrous or pubescent.

cylindrical spikes, densely flowered, 20–50 × 5–8 mm, solitary or in fascicles of 2 or 3 in leaf axils.

20–200+-flowered, terminal or axillary, globose heads or cylindrical spikes, heads solitary, fascicled, or clustered, or arranged in pseudoracemes or pseudopanicles;

bracts present.

0–2 mm.

usually not elongated in fruit, glabrous or pubescent.

4-merous, bright yellow;

calyx 0.6–0.9 mm;

corolla 1.5–2.1 mm;

filaments 2.6–3.6 mm;

ovary pubescent.

mimosoid;

calyx cup-shaped, lobes 4 or 5, triangular, glabrous [pubescent];

corolla yellow to cream, cup-shaped, lobes 4 or 5, triangular, membranous, glabrous [pubescent];

stamens 20–150, rarely connate basally, usually exserted, mostly yellow to gold or creamy white;

anthers dorsifixed, mostly eglandular;

ovary sessile or short-stipitate;

style and stigma filiform.

legumes, erect to pendulous, stipitate, stipe usually relatively short, mostly flat, straight to falcate, linear to oblong, apex sometimes beaked, usually dehiscent along sutures, dry, papery to leathery, glabrous or pubescent.

elliptic in cross section, linear, 50–150 × 5–9 mm, somewhat constricted between seeds.

aril light yellow, folded several times into thickened, lateral, skirtlike aril covering seed apex.

usually 6–10, usually flattened, ellipsoid to ovoid, uniseriate, usually with pulpy, bright-colored aril, forming a cap or encircling seed.

= 13.