Common Name: AMARANTH FAMILY
Habit: Annual to subshrub; monoecious and/or dioecious; occasionally spiny; hairs simple (branched). Leaf: blade simple, alternate or opposite, margins entire or serrate; veins pinnate; stipules 0. Inflorescence: axillary or terminal; 3-flowered cymes in dense spikes, heads or panicles; bracts 0 or 1--5, persistent; bractlets 0--2. Flower: bisexual or unisexual, small, green (+- white), yellow or purple; perianth parts 0 or (1)3--5, free or fused basally, scarious or hardened, persistent; stamens 1--5, opposite perianth parts, free or basally fused as a tube, generally unequal, occasionally alternate with appendages on stamen tubes (pseudostaminodes), anthers 2- or 4-chambered; ovary superior, chamber 1; ovule 1 (2--many); style (0)1--3, stigmas 1--3(5). Fruit: utricle; generally with persistent perianth or bracts. Seed: 1 [2+], small, lenticular to spheric, smooth or dotted to striate or tubercled.
Genera In Family: +- 75 genera, 900 species: cosmopolitan, especially disturbed, arid, saline or alkaline soils; some cultivated for food, ornamental; many naturalized, ruderal or agricultural weeds. Note: Amaranthaceae including Chenopodiaceae by some. Polycnemoideae, represented in California by Nitrophila, formerly considered subfamily of Chenopodiaceae, but needs further research. Guilleminea densa (Willd.) Moq. var. aggregata Uline & W.L. Bray is a waif. Froelichia gracilis (Hook.) Moq. possibly naturalized.
eFlora Treatment Author: Mihai Costea, except as noted
Scientific Editor: Douglas H. Goldman, Bruce G. Baldwin.

Habit: [Annual] perennial herb, aquatic to terrestrial. Stem: prostrate or ascending; hairs simple. Leaf: opposite, subsessile to short-petioled, blade margins entire to serrate. Inflorescence: axillary or axillary and terminal, sessile or peduncled, many-flowered cylindric spikes or spheric heads; bracts and bractlets persistent, scarious. Flower: bisexual; perianth parts 5, free, +- equal or not, scarious, persistent, white, glabrous or woolly; stamens 3--5, fused at base into short tube or cup, anthers 2-chambered; pseudostaminodes 5, alternate with stamens; ovary obovoid to +- spheric; style short, +- 0.2 mm; stigma spheric (2-lobed), ovule 1, pendent. Fruit: indehiscent; fruit wall membranous. Seed: 1, lenticular or ovoid-oblong, +- red brown, smooth, shiny.
Etymology: (Latin: alternating pseudostaminodes and stamens) Note: Alternanthera sessilis (L.) DC. occasionally a greenhouse weed ; Alternanthera ficoidea (L.) P. Beauv. var. bettzickiana (Regel) Backer widely cultivated, California reports unconfirmed.