An Illustrated Flora of the Northern United States, Canada and the British Possessions/Commelinaceae
Perennial or annual leafy herbs with regular or irregular perfect and often showy flowers in cymes, commonly subtended by spathe-like or leafy bracts. Perianth of 2 series; a calyx of mostly 3 persistent sepals, and a corolla of mostly 3 membranous and deciduous or fugacious petals. Stamens mostly 6, hypogynous, rarely fewer, all similar and perfect or 2 or 3 of them different from the others and sterile; filaments filiform or somewhat flattened; anthers 2-celled, mostly longitudinally dehiscent. Ovary superior, sessile or very nearly so, 2-3-celled ; ovules 1 or several in each cell, anatropous or half anatropous ; style simple ; stigmas terminal, entire or obscurely 2-3-lobed. Seeds solitary or several in each cell of the capsule. Capsule 2-3-celled, loculicidally 2-3-valved. Embryo small. Endosperm copious.
About 25 genera and 350 species, mostly natives of tropical regions, a few in the temperate zones.