A subclass of the class Liliopsida (monocotyledons) of the division Magnoliophyta (Angiospermae), the flowering plants, consisting of four orders (Arecales, Cyclanthales, Pandanales, and Arales), five families, and nearly 6000 species. Except for the highly reduced family Lemnaceae (Arales), they have an inflorescence of usually numerous, small flowers, generally subtended by a prominent spathe and often aggregated into a spadix. Except in the Araceae (Arales), the endosperm seldom contains much starch.