Flora of North America species comparison

erect or sometimes ascending proximally, much-branched and bushy, rarely nearly simple, 0.3–1(–2) m; each node with paired, divergent spines (modified bracts) to 1.5(–2.5) cm.

erect, green, branched, 0.3–1 m. Leaves: petiole of proximal leaves equaling or longer than blade, becoming shorter distally;

blade rhombic-ovate or ovate to elliptic, 3–12 × 2–8 cm, base broadly cuneate, margins entire, apex slightly acuminate to obtuse and faintly emarginate, mucronate.

petiole ± equaling or longer than blade;

blade rhombic-ovate, ovate, or ovate-lanceolate, 3–10(–15) × 1.5–6 cm, base broadly cuneate, margins entire, plane or slightly undulate, apex acute or subobtuse to indistinctly emarginate, mucronulate.

of pistillate flowers lanceolate to ovate-lanceolate, shorter than tepals, apex attenuate.

lanceolate, shorter than 2 mm, shorter than tepals, apex spinescent.

simple or compound terminal staminate spikes and axillary subglobose mostly pistillate clusters, erect or with reflexed or nodding tips, usually green to silvery green.

terminal panicles and axillary spikes;

panicles erect or often drooping, green, dense, branched, leafless at least distally.

often terminal or in proximal glomerules;

tepals 5, equal or subequal, 1.7–2.5 mm;

stamens 5.

usually clustered at tips of inflorescence branches, sometimes gathered in proximal glomerules (as in A. spinosus);

tepals 5, equal or subequal;

stamens 5.

tepals 5, obovate-lanceolate or spatulate-lanceolate, equal or subequal, 1.2–2 mm, apex mucronate or short-aristate;

styles erect or spreading;

stigmas 3.

tepals 5, oblong-spatulate to oblong, not clawed, 1.5–2 mm, apex acute, often very shortly mucronate;

style branches strongly spreading, shorter than body of fruit;

stigmas 3.

black, lenticular or subglobose-lenticular, 0.7–1 mm diam., smooth, shiny.

dark reddish brown to black, subglobose or lenticular, 0.8–1 mm diam., shiny, smooth.

ovoid to subglobose, 1.5–2.5 mm, membranaceous proximally, wrinkled and spongy or inflated distally, irregularly dehiscent or indehiscent.

ovoid or subglobose, 1.5–2 mm, slightly shorter than tepals, smooth to irregularly wrinkled, dehiscence regularly circumscissile.

= 64.