Jepson eFlora Taxon Page

Common Name: AMARANTH FAMILY
Habit: Annual to shrub; hairs simple, stellate, glandular or 0, sometimes scaly, mealy, or powdery from collapsed glands, occasionally spiny; monoecious, dioecious, with bisexual flowers, or with both bisexual and unisexual flowers. Stem: occasionally fleshy. Leaf: blade simple, alternate or opposite, occasionally fleshy or reduced to scales, margins entire or serrate to lobed; veins pinnate; stipules 0. Inflorescence: axillary or terminal; raceme, spike, panicle, catkin-like, spheric head, axillary clusters, 3-flowered cymes, or flowers 1; bracts 0--5, bractlets 0--2, leaf-like, generally persistent or strongly modified in fruit, winged, tubercled, spiny, or not. Flower: bisexual or unisexual, small, green (+- white), yellow or purple; sepals 0 or (1)3--5, free or fused basally (or +- throughout), leaf-like, scarious, membranous, fleshy, or hardened and persistent, deciduous or not, often strongly modified in fruit; petals 0; stamens 1--5, opposite sepals, filaments free or basally fused as a tube, equal or unequal, occasionally alternate with appendages on stamen tubes (pseudostaminodes), anthers 2- or 4-chambered; ovary superior (1/2-inferior), chamber 1; ovule 1 (2--many); styles 1--5, or 0 with stigmas sessile, stigmas 1--5. Fruit: achene or utricle, generally falling with persistent calyx or bracts. Seed: 1[2+], small, lenticular to spheric; seed coat smooth or dotted to striate or tubercled, net-like, or prickly, margin occasionally winged.

Genera In Family: +- 175 genera, 2400 species: worldwide, especially disturbed, arid, saline or alkaline soils; some ornamental; some cultivated for food (Beta vulgaris subsp. vulgaris, beet, Swiss chard; Spinacia oleracea L., spinach; Chenopodium quinoa Willd., quinoa); and some worldwide, naturalized ruderal or noxious agricultural weeds. Note: Now treated to include all taxa previously in Chenopodiaceae based on recent studies (Morales-Briones et al. 2021). Taxa previously in Monolepis treated in Blitum, Micromonolepis, Neomonolepis. Sarcobatus treated in Sarcobataceae. Guilleminea densa (Willd.) Moq. var. aggregata Uline & W.L. Bray is a waif. Froelichia gracilis (Hook.) Moq. possibly naturalized. Native spp. of Kochia now treated in Neokochia.

eFlora Treatment Author: Nuri Benet-Pierce, Michael G. Simpson, & Mihai Costea
Scientific Editor: Bruce G. Baldwin, Douglas H. Goldman, David J. Keil, Thomas J. Rosatti, Margriet Wetherwax.

Common Name: AMARANTH, PIGWEED
Habit: Annual (short-lived perennial herb); monoecious or dioecious. Stem: prostrate to erect, branched or not. Leaf: alternate, petioled, ovate to linear, tip often +- notched (2-lobed), midvein ending in sharp point, margin entire, flat or wavy. Inflorescence: 3-flowered cymes, in dense axillary clusters, or large, terminal, panicle- or spike-like inflorescence; bract 1, bractlets 0--2, alike, persistent, spine-like to +- leaf-like or +- membranous, at least margins scarious-membranous. Flower: unisexual. Staminate Flower: perianth parts (2)3--5, scarious; stamens (1)2--5, filaments free; pseudostaminodes 0; anthers 4-chambered. Pistillate Flower: perianth parts (1)3--5, membranous or scarious, free, persistent; ovary ovoid, style 0, stigmas 2--3, persistent, slender, papillate; ovule 1, erect. Fruit: circumscissile or indehiscent, ovoid to obovoid, smooth or +- wrinkled, tip +- gradually (abruptly) narrowed to stigmas or beak; walls thin, membranous. Seed: 1, lenticular to +- spheric, round to obovate, smooth, shiny, occasionally obscure-dotted or -net-like, +- white-ivory to brown-red or black.

Etymology: (Greek: unfading, non-withering) Note: Hybrids common, F1 generally with numerous, densely packed bractlets beneath generally sterile pistillate flowers, abnormal-shaped inflorescence with dense, twisted or fan-shaped branches. Unless otherwise noted, descriptions of bracts and flower parts are of pistillate flowers.

Unabridged Note: F1 hybrids have been observed in natural conditions or have been experimentally obtained between any of the following species: Amaranthus hybridus, Amaranthus powellii, Amaranthus retroflexus, Amaranthus tuberculatus, Amaranthus palmeri, Amaranthus caudatus, Amaranthus hypochondriacus, Amaranthus cruentus, Amaranthus spinosus, Amaranthus blitoides, Amaranthus albus. Amaranthus caudatus L., Amaranthus cruentus L., Amaranthus hypochondriacus L. frequently cultivated as ornamentals, occasionally escaping from cultivation. Amaranthus spinosus L. probably not naturalized, uncommon waif.

Common Name: PALMER'S AMARANTH
Habit: Dioecious. Stem: erect, 20--200(250) cm, branched or not, green, +- glabrous. Leaf: petiole 60--90 mm; blade 15--150 mm, 10--35 mm wide, ovate, rhombic-ovate to lanceolate, base +- wedge-shaped, tip +- obtuse to acute, margins flat. Inflorescence: terminal, simple or panicle-like, +- flexible to drooping, main axis 10--35(50) cm, 1--1.8(2.5) cm wide (including flowers), green; staminate bracts 4--6 mm, >= outer perianth parts, spine-like; pistillate bracts 4--6 mm, 1.3--2 × > perianth, spine-like, lance-ovate. Flower: staminate perianth parts 5, unequal, outer (2.5)3--6 mm, acuminate, spine-tipped, inner 2.5--3 mm, obtuse, notched, stamens 5; pistillate perianth parts 5, unequal, outer 3--4 mm, lanceolate, +- acuminate, inner 1.7--2.5 mm, obovate to spoon-shaped, rounded to +- notched and mucronate; stigmas 2(3), spreading. Fruit: circumscissile; 1.5--2 mm, < perianth, +- spheric to obovoid, brown to occasionally red-brown, smooth or +- rough near tip. Seed: 1--1.4 mm wide, lenticular, elliptic to obovate, dark red-brown to black, smooth, shiny. Chromosomes: 2n=32, 34.