Small shrubs, subshrubs, or herbs, without stinging hairs. Leaves apparently alternate, distichous; nanophylls present or absent, opposite to normal leaves; stipules 2; leaf blade 3-veined, one or both major lateral veins sometimes inserted above the base, or pinnately veined, base asymmetric, cystoliths linear or fusiform. Inflorescences usually pedunculate, mostly many-flowered or rarely 1-3-flowered discoid capitula, capitula usually 2-valved, each valve with several glomerules of several flowers and subtended by a few bracteoles; unisexual (plants monoecious or dioecious); male inflorescences usually with discoid receptacle (pyriform young receptacle in E. brachyodotnum and E. ficoides), rarely cymose; female ones with discoid receptacle and bracteoles along margin. Male flowers: perianth lobes 4 or 5, elliptic, connate at base, usually corniculate or short horned below apex; stamens as many as and opposite to perianth lobes; filaments of stamens inflexed in bud; rudimentary pistil small or absent. Female flowers: perianth lobes 4 or 5, or reduced, less than 1/2 length of ovary, free or connate at base, not corniculate at apex; staminodes 3-5, linear. Ovary straight, ellipsoid; style absent; stigma penicillate; ovule orthotropous. Achenes ovoid or ellipsoid, slightly flattened, mostly longitudinally 6-10-ribbed, rarely smooth or tuberculate.
Inflorescences unisexual, axillary, sessile (in Flora area), consisting of very densely clustered flowers and surrounded by almost free bracts in the ♂ inflorescences or by somewhat fused bracts in the ♀ inflorescences
Leaves alternate, distichous, sessile or very shortly petiolate, asymmetrical; stipules completely or partly fused, intrapetiolar (however, the presence of vestiges of 2 pairs of stipules indicates that the genus has basically opposite leaves, but one leaf of each pair is rudimentary or totally reduced), stipules of reduced leaf different in size and sometimes also in form from those of extant leaf
Male flowers 4–5-merous, tepals generally with a horn-like dorsal appendage; rudimentary ovary poorly developed or absent
Achene ovate, small, ejected by the reflexed staminodes.
Female flowers with 3–5 very reduced tepals and 3 scale-like staminodes, sometimes sterile; ovary ovoid, with penicillate stigma
Stems prostrate and ascending, with the regularly arranged leaves forming flattened aerial shoots
Erect annual and perennial monoecious herbs
Female flowers with 3–5 very reduced tepals and 3 scale-like staminodes, sometimes sterile; ovary ovoid with a penicillate stigma.
Achene ovoid, small, ejected by the reflexing of the staminodes.
Inflorescences unisexual, axillary, sessile (in the Flora Zambesiaca area), consisting of very densely clustered flowers and surrounded by almost free bracts in the male inflorescences or by somewhat fused bracts in the female inflorescences.
Male flowers 4–5-merous, tepals generally with a horn-like dorsal appendage; rudimentary ovary absent or indistinct.
Leaves distichous, apparently alternate, sessile or very shortly petiolate, asymmetrical; stipules fused, intrapetiolar, (the presence of 2 pairs of stipules indicates that the genus has opposite leaves but one leaf of each pair is rudimentary or totally reduced).
Erect annual or perennial, monoecious herbs.
Herbes'annuelles ou vivaces, souvent délicates.'Feuilles'alternes (par avortement de l'une des feuilles de chaque paire), distiques, sessiles ou brièvement pétiolées, asymétriques, en général serretées et trinerves, à cystolithes linéaires.'Inflorescences'axillaires, à cymules réunies sur un réceptacle et entourées d'un involucre.'Fleurs'♂ sessiles ou pédicellées, 4-5-mères; segments du périgone appendiculés sous le sommet; périgone ♀ à 3 (5) segments très petits (plus courts que l'ovaire); staminodes comme dans'Pilea , ou nuls.'Akènes ovales ou elliptiques, comprimés ou subprismatiques.\n\t\t\t\tEnviron 60 espèces, surtout asiatiques et océaniennes, 3 (ou 6? au Congo belge. Plantes de sous-bois ou lieux humides et ombragés, surtout dans les montagnes de l'Est.