AMARANTHACEAE  

Annual or rarely perennial herbs, erect or decumbent, glabrous or furnished with short and gland-like or multicellular hairs; plants monoecious or dioecious. Leaves alternate, simple, entire or sinuate, long-petiolate. Inflorescences basically cymose, of dense to lax axillary thyrses or upper clusters dense, leafless, aggregated and spike-like, bracteate. Flowers unisexual or bisexual; bracteoles 2-5, small and herbaceous or membranous and spinescent. Tepals (1-3)5, glabrous, membranous, equal or subequal, free or connate below and somewhat indurate, occasionally absent in flowers of dioecious spp. Stamens as many as tepals; filaments free at base; pseudostaminodes absent; anthers 2-thecous. Ovary ellipsoid, compressed; ovule solitary, subsessile, erect; style short or absent; stigmas 2 or 3, subulate or filiform. Fruit a dry capsule, usually enclosed in perianth, indehiscent or circumscissile, sometimes 2- or 3-toothed at apex. Seed globose or compressed, black, smooth and shiny; testa thin; embryo annular; endosperm present. x= 17, 8 (7, 9, 10, 12) (high polyploidy) .

Perennial herbs (sometimes flowering in first year), prostrate to erect or scandent. Leaves opposite or alternate, entire, flat. Inflorescences axillary and terminal, sessile or pedunculate, woolly spikes, or spikes arranged in a loose panicle, bracteate. Flowers unisexual or bisexual, plants probably sometimes polygamous, solitary in axils of bracts; bracteoles 2; bracteoles and perianth falling together with fruit but bracts and bracteoles persistent. Tepals 5, free, oval, or lanceolate-oblong, sometimes unequal, some or all softly woolly, with membranous margin and a thin to wider green centre. Stamens (and subulate staminodes of female flowers) 5; filaments connate at base into a basin or cup, alternating with subulate to oblong pseudostaminodes; anthers 2-thecous. Ovary small; ovule solitary, suspended from an elongated basal funicle; style shorter or longer than ovary; stigmas 2 or capitellate. Capsule thin-wall, delicate, bursting irregularly, membranous, enclosed in perianth. Seed compressed-reniform, firm, black. x= 7, 8, 9, 10, 11 (polyploidy) .

Erect perennial herbs, sometimes bushy or scandent, sometimes flowering in first year. Leaves opposite, entire, petiolate. Inflorescence a +/- slender, simple or branched, elongated solitary or fasciculate spike up to 0.3 m long, terminal on stem and branches, flowers at first congested and +/- patent, finally usually laxer and deflexed; bracts deltoid, ovate or acuminate, midrib excurrent in a spine, deflexed in fruit, persistent. Flowers bisexual, solitary in axils of bracts; bracteoles 2, spinous-aristate with excurrent midrib, lamina forming short and free to longer and adnate membranous wings; entire flower with bracteoles falling with ripening of seed. Tepals 4 or 5, 1-3(-5)-nerved, narrowly lanceolate, acuminate, mucronate with excurrent midrib, indurated in fruit especially at base. Stamens 2-5; filaments filiform, monadelphous at base, alternating with usually fringed pseudostaminodes; anthers 2-thecous. Ovary turbinate or obovoid; ovule solitary from apex of an elongated basal funicle; style cylindrical, variable in length; stigma capitellate. Capsule thin-walled, indehiscent. Seed cylindrical; perisperm/endosperm copious. x= 7 (aneuploids, high polyploidy ).