Laticifers absent, raphides absent. Herbs, stem a repent, much-branched, lacunose rhizome with aromatic oil cells. Leaves distichous, unifacial, ensiform, not differentiated into petiole and blade, intravaginal squamules present in leaf axils; primary veins parallel, higher order venation parallel. Inflorescence solitary, terminal, borne laterally on leaf-like scape, continuation shoot arising in axil of leaf preceding spathe. Spathe longer than spadix, erect, persistent, appearing merely as a vertical extension of the leaf-like peduncle. Spadix jutting out at an angle from peduncle, conoid and finger-like or slender and tail-like. Flowers bisexual, perigoniate, densely arranged, bractless, 3-merous; tepals 6, in 2 whorls of 3, thin, fornicate. Stamens 6, in 2 whorls of 3, filaments linear, anthers introrse, thecae rounded-elliptic, subopposite, dehiscing by longitudinal slit, connective inconspicuous. Pollen monosulcate to subulcerate, ellipsoid, small (mean 18 µm; range 15-20 µm), exine shallowly and remotely or more densely foveolate, otherwise psilate, apertural exine subpsilate. Gynoecium obconic-oblong, equalling tepals, 2-3-locular, ovules several per locule, pendent, orthotropous, both integuments bearing trichomes, inner integument longer than outer and forming micropyle, placenta apical, stigma minute, sessile. Berry oblong-obovoid with thin, leathery pericarp, enclosed by tepals, 1-5(-9)-seeded, whitish with brownish stigma remnant when fresh, soon drying to straw-brown. Seed oblong to ellipsoid, testa light brown, foveolate (A. calamus) or smooth (A. gramineus), long integumentary trichomes present (A. gramineus) or absent, embryo axile, cylindric or conoid (A. gramineus), perisperm present, endosperm copious.