Flora of North America species comparison

erect, branched, usually (0.3–)0.5–1.5(–3) m;

proximal branches often ascending.

erect, often branched, 0.8–1.5 m.

long-petiolate;

blade obovate or rhombic-obovate to elliptic proximally, sometimes lanceolate distally, 1.5–7 × 1–3.5 cm, base broadly to narrowly cuneate, margins entire, plane, apex subobtuse to acute, usually with terminal mucro.

petiole 1/2 as long as blade;

blade ovate, elliptic, rhombic, or lanceolate, mostly 4–12 × 1.4–6 cm, base tapering, margins entire, usually undulate, apex acuminate and short-mucronate;

distal leaf blades green, red, scarlet, maroon, purple, yellow, and cream (unique to A. tricolor).

of pistillate flowers with long-excurrent midrib, 4–6 mm, longer than tepals, apex acuminate or mucronulate; of staminate flowers, 4 mm, equaling or longer than outer tepals, apex long-acuminate.

of pistillate flowers ovate to lanceolate, 5–6 mm.

terminal, linear spikes to panicles, usually drooping, occasionally erect, especially when young, with few axillary clusters, uninterrupted or interrupted in proximal part of plant.

axillary glomerules.

tepals 5, unequal, 2–4 mm, apex acute;

inner tepals with prominent midrib excurrent as rigid spine, apex long-acuminate or mucronulate;

stamens 5.

intermixed with pistillate;

tepals 3;

stamens 3.

tepals 1.7–3.8 mm, apex acuminate, mucronulate;

style branches spreading;

stigmas 2(–3).

tepals 3, narrowly ovate to lanceolate, 5–6 mm, apex aristate;

style branches spreading;

stigmas 2–3.

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

black or brownish black, subglobose, 1 mm diam., shiny.

tan to brown, occasionally reddish brown, obovoid to subglobose, 1.5–2 mm, shorter than tepals, at maturity walls thin, almost smooth or indistinctly rugose.

ovoid, 2–2.5 mm, rugose, dehiscence regularly circumscissile.