Rhizomes nodular or rarely elongate, often lobed, lacking scales, sometimes with root-like processes. Inflorescence mostly monoecious and proterogynous or rarely dioecious, claviform, the peduncle encircled at the base with a glabrous annular to cupuliform sheath which is sometimes very obscure, naked above the sheath, the head globose or ellipsoid, when immature covered with 6-sided, peltate, umbonate scales underneath which occurs a dense mat of paraphysoid trichomes and young developing flowers, the scales deciduous prior to anthesis. Perianth of the staminate flowers tubular, conical or subcampanulate, completely connate, crenate; in the pistillate flowers reduced to a low epigynous collar or, according to some authors, absent-Stamens 3, exserted, the filaments completely fused into a staminal column free from the perianth tube, the anthers united into a synan-drium, each with two large lateral pollen sacs, introrse; absent in the pistillate flowers. Pistil 2-carpellate, the ovary compressed, the ovules 2, fused to the ovary wall, generally only one maturing, the styles 2, filiform, spreading, deciduous, the stigmas globose or capitate; pistillode present in the staminate flowers. Fruit nut-like, compressed, with crusty epicarp and hard endocarp.
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