HABIT : evergreen herbs, rhizome thick, creeping, internodes short. LEAVES : several. PETIOLE : usually smooth, rarely shortly and sparsely spiny, geniculate apically, sheath relatively short. BLADE : lanceolate, ovate, elliptic, nearly triangular to subsagittate, subcordate, auriculate, hastate to trifid, mostly coriaceous, completely glabrous or midrib and primary lateral veins densely pilose abaxially; primary lateral veins pinnate, secondary lateral veins parallel-pinnate, tertiaries transverse between them. INFLORESCENCE : 1-3 in each floral sympodium. PEDUNCLE : ± as long as petiole or shorter. SPATHE : elliptic-ovate or ovate, not constricted, only weakly differentiated into tube and blade, widely expanded at anthesis, but always slightly convolute at base, closing after anthesis and persistent to fruiting stage, uniformly coloured, mostly green or cream to reddish tinged, paler within. SPADIX : cylindric, shorter or sometimes much longer than spathe, female zone free, usually densely flowered, rarely somewhat laxly flowered, shorter than male and contiguous with it or rarely with few sterile or irregular, bisexual flowers in between, male zone fertile to apex. FLOWERS : unisexual, perigone absent. MALE FLOWER : 3-8-androus, stamens connate, synandrium ± obpyramidal, filaments connate, sometimes fairly long, fused connectives thick, fleshy, sometimes covered by thecae and inconspicuous, often only incompletely connate at apex, with shallow fissures in between, thecae lateral or marginal or covering nearly the whole synandrium from apex to base (A. pynaertii), dehiscing by longitudinal slit. POLLEN : inaperturate, subspheroidal to spherical, small (mean 24 µm., range 20-31 µm.), exine perfectly psilate to obscurely verrucate and/or dimpled. FEMALE FLOWER : gynoecium depressed-globose to ovoid, ovary (1-)2-3-locular, ovules many per locule, anatropous, placenta axile, style narrower than ovary, stigma broad, discoid, green, pink or white. BERRY : depressed-globular to obovoid, green to pale green, many-seeded. SEED : small, irregularly ovoid to subcylindric, testa rough, thickish, embryo axile, elongate, endosperm copious.
Helophytic or rheophytic; petioles geniculate apically; flowers unisexual, perigone absent; placenta axile, ovules many per locule. Differs from Neotropical Dieffenbachia and Bognera in the female zone not adnate to the spadix and its tropical west and central African range. Differs from Homalomena in African range and in stamens of each male flower entirely connate into a distinct synandrium.