Flora of North America species comparison

erect, branched, stout to robust, usually 1.5–3 m (occasionally to 9 m!) × 30 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 1/3–2/3 length of blade;

blade narrowly lanceolate to narrowly ovate, 10–20 × 1–4 cm, base cuneate, margins entire, plane, apex acute or long-attenuate to acuminate.

of pistillate flowers 1.5–2 mm; of staminate flowers with moderately heavy midribs, 1.5–2 mm.

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

mostly terminal, linear spikes to panicles, usually interrupted.

terminal panicles and axillary spikes;

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

tepals 5, inner tepals with moderately prominent, excurrent midribs, equal, 2–2.5 mm, apex subacute to mucronulate;

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 absent;

style branches spreading;

stigmas 3–5.

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.

reddish brown to dark brown, 1–1.2 mm diam., shiny.

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

stramineous to brown, with 3(–5) longitudinal ridges corresponding to 3–5 style branches, elliptic or obovoid, 1.5–2.5 mm, slightly fleshy, smooth (slightly rugose in herbarium specimens).

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

= 64.