Melanthiaceae is a family of mostly perennial genera, many formerly included in Liliaceae . Leaves are usually linear or lanceolate, sessile and sheathing, alternate, spiral or in 2 distinct ranks. Flowers are in formed in racemes, spikes, or panicles. The flowers have 6 free to joined tepals, in 2 whorls. There are 6 stamens. APG II expanded this family to include Trilliaceae but genera in that group are not always included by others.
This family is broken into these five groups by some taxonomists:
Meliantheae, more or less bulbous, from the Northern Hemisphere with one species from Peru. Genera in this group are Amianthium, Anticlea, Melanthium, Schoenocaulon, Stenanthium, Toxicoscordion, Veratrum, and Zigadenus
Chionographideae, rhizomatous, from eastern North America and east Asia including Chamaelirium and Chionographis
Xerophylleae, bulbous, rhizomatous, from North America represented by Xerophyllum