Flora of North America species comparison

simple or more commonly branched throughout, mainly 2–8(–10) dm, branches mostly obtusely angled;

herbage scurfy, becoming glabrate.

alternate or proximalmost opposite, short petiolate proximally, sessile and often cordate-clasping distally;

blade ovate to deltoid or oval, 4–30(–40) × 3–30 mm, base truncate or subhastate to rounded, margin entire or dentate, apex acute to obtuse.

usually with or, uncommonly, without Kranz anatomy.

in axillary glomerules.

in glomerules mainly in distal axils;

sepals 3–5.

with calyx lobes crested or not.

lacking or rarely with a perianth (in A. covillei, A. pleiantha, and A. suckleyi), enclosed by a pair of bracteoles.

brown, 1–2 mm wide.

erect;

radicle typically superior (except in A. pleiantha), erect, tip adjacent to styles.

bracteoles scarcely compressed, 2–3 mm and as wide, apex truncate to broadly rounded, with 3 (or more) teeth across summit, surfaces smooth (or rarely tuberculate).

cuneate to ovate or obovate united at least to middle, faces with tubercles or crests or smooth.

= 18.