Morphological characters and geographical distribution are the same as those of the family.
Herbs with milky sap. Leaves sheathing at base; axillary scales present. Inflorescences branched [unbranched], projected above water. Flowers bilaterally symmetric, sessile; stamens 6--18--; filaments distinct; anthers 2-locular; pistils 2--6[--9], sessile. Fruits: beak terminal [lateral], curved or straight. Seeds: endosperm absent; seed coat single or double. x = 8.
Perianth-segments 1-3, white or coloured
Scapes simple or bifid, with unilateral flowers
Tuber globular to oval or more irregular in shape, usually grey to brown with very numerous roots from upper part Leaves usually with a long petiole and a distinct blade with a few parallel primary veins and numerous transverse secondary veins, but in some species, e.g. A. vallisnerioides, the leaf-blade is linear
Inflorescence with spirally or unilaterally arranged flowers in a loose or dense simple or bifid spike; spathe present, but usually very early caducous
Flowers with white, yellow, mauve or bluish-violet petal-like appendages (tepals), rarely with tepals lacking
Small to medium-sized perennial herbs growing in seasonally wet soil or submerged in temporary pools or similar habitats, rarely in permanent water; leaf-blades and flowers often floating on the surface of the water
Stamens with yellowish or brown anthers often early turning blackish; connnective sometimes protruding into a conical appendage; pollen-grains monosulcate, borne in monads
|[Greek, from aquatic habitat]|