Sp. Pl. 1: 324. 1753; Gen. Pl. ed. 5; 151, 1754.
Herbs, wetland. Rhizomes vertical. Leaves appearing before flowers, several, emergent or sometimes floating, clustered; petiole longer than blade; blade abaxially paler green, adaxially dark bluish green with distinctive velvety sheen, simple, not peltate, oblongelliptic, base acute to obtuse or sometimes oblique, apex rounded-apiculate or short-acuminate; venation parallel to midvein except near base. Inflorescences: peduncle reclining in fruit, usually equal to or longer than leaves, apex swollen; spathe absent; spadix long-conic. Flowers mostly bisexual, the distal staminate; perianth present. Fruits partially embedded in spadix, green to blue-green. Seed 1, embedded in mucilage. x = 13.
e United States, primarily on coastal plain
The leaf sheathing the peduncle, which has been interpreted as the spathe in Orontium, is a sympodial leaf and is not equivalent to the spathe of other Araceae (T. S. Ray 1988). Orontium also differs in several other characteristics from the presumably related genera Lysichiton and Symplocarpus and has been segregated as a monogeneric tribe (M. H. Grayum 1990).