AMARANTHACEAE  

Erect annual herbs. Leaves opposite, entire, linear to oblong. Inflorescences elongate or subglobose, densely pilose spike-like thyrses terminal on stem and branches, shortly or long-pedunculate or subtended by 1 or 2 reduced leaves; each bract subtending a bibracteolate partial inflorescence consisting mostly of a triad of a central bisexual flower and 2 lateral modified sterile flowers consisting of slender, finally spinous, processes; partial inflorescences falling as a unit complete with bracteoles; bracts persistent on inflorescence axis. Tepals 5, narrow, 3- or 5-nerved, free, oblong or oblong-lanceolate, mucronate, with broad, membranous margins, only a narrow central section coloured. Stamens 5; filaments fused into a cup at base, usually alternating with very short, blunt pseudostaminodes; anthers 2-thecous. Ovary scarcely compressed, considerably pilose above and with a distinct horn on one side below its apex; ovule solitary, suspended from a basal funicle; style simple; stigma capitate. Capsule +/- compressed, irregularly ruptured below by developing seed, rounded apex densely pilose, gibbous to one side of style with a short horn-like process. Seed suborbicular; perisperm/endosperm copious.

Prostrate or decumbent, mat-forming perennial herb with a thickened rootstock, pubescent. Leaves opposite, entire, +/- elliptic, petiolate. Inflorescences sessile, axillary, dense, often fasciculate spikes, bracteate; bracts persistent, subequal, silvery, +/- ovate. Flowers bisexual, minute, solitary in axils of bracts; bracteoles 2; perianth and bracteoles falling with fruit. Tepals 5, elliptic, oblong or ovate, acute, woolly at base, hyaline, or firm with 3 green nerves, free or connate to +/- halfway; perianth and bracteoles falling with fruit. Stamens 5, perigynous; filaments fused into a tube, tube adnate to perianth; anthers 1-thecous. Ovary compressed; ovule solitary, pendulous; style usually short; stigma shortly bilobed. Capsule membranous, thin-walled, indehiscent. Seed compressed, firm.

Annual or perennial herbs, sometimes woody at base, sometimes decumbent. Leaves opposite, entire, petiolate, sessile or subsessile, usually pubescent. Inflorescences terminal on stem and branches, spiciform or capitate, bracteate, ultimate division basically a triad of 1 central bisexual fertile and 2 modified sterile flowers formed of uncinate, straight or glochidiate spines or bracteoliform processes; bracts ovate, usually aristate, accompanied by 2 bracteoles, persistent, finally +/- deflexed; bracteoles and perianth, all or part, falling as a burr in fruit. Tepals 5, free, subequal, very shortly mucronate or some hooked-aristate, often pilose. Stamens 5, shortly monadelphous at base; filaments linear, alternating with fringed pseudostaminodes; anthers 2-thecous. Ovary obovoid; ovule solitary, suspended from an elongated, basal funicle; style slender; stigma capitate. Capsule thin-walled, indehiscent, closely held in perianth. Seed ovoid, slightly compressed; perisperm/ endosperm copious. x= 17 (7, 8) (polyploidy) .

Erect perennial herbs or subshrubs; stems sometimes tuberculate. Leaves opposite, entire. Inflorescences pedunculate or sessile spike-like bracteate thyrses, each bract with a partial inflorescence of 1 or 2 bisexual flowers and 2 or 3 modified sterile flowers consisting of single very rapidly developing spines, partial inflorescence falling as a 2- or 3-spined burr. Tepals 5, inner becoming narrower, outer several-nerved, hardened at base, woolly on back. Stamens 5, unequal; filaments filiform, flattened, connate at extreme base; pseudostaminodes 0; anthers narrow, 2-thecous. Ovary +/- compressed, glabrous; ovule solitary, basal; style slender, with 2 short or elongated stigma branches. Capsule scarcely compressed, delicate except for a small firm area about base of style, irregularly ruptured by developing seed, thin-walled, indehiscent. Seed +/- horseshoe-shaped; perisperm/endosperm copious.

Small, much-branched subshrubs, rigid and twiggy; young branches very shortly woolly. Leaves alternate or occasionally opposite, sometimes much reduced, fleshy. Inflorescences short to subcapitate spikes, bracteate. Flowers bisexual, solitary in axils of bracts; bracteoles 2. Tepals 5, free, stiffly membranous, subequal, with straight, silky hairs on back. Stamens 5; filaments fused to the quadrate to deltoid, fringed or entire pseudostaminodes; anthers 2-thecous. Ovary ovoid or turbinate, glabrous or downy; ovule solitary, suspended from an elongated basal funicle; style slender; stigma capitate. Capsule thin-walled, indehiscent.