OregonFlora species comparison

erect to prostrate or spreading; woody or herbaceous, usually branched;

branches sometimes forming spine-like appendages in shrubs.

alternate; opposite below, sometimes hastate;

margins entire or toothed or lobed; flat, sessile or petiolate.

axillary or terminal clusters of flowers, sometimes forming panicles or spikes.

unisexual, sometimes intermixed in monoecious plants, staminate and pistillate flowers distinct;

perianths not scarious.

usually with 5-parted perianths;

stamens (3)5;

bracteoles absent.

usually without perianth and enclosed by 2 fruiting, glabrous to short–pubescent bracteoles (but with deeply lobed, 5-parted perianths in A. hortensis), sometimes dimorphic.

with membranous; free pericarp.

usually vertical, sometimes horizontal; of 1 kind or sometimes dimorphic, brown or black; shiny.