Like the family as a whole, members of the tribe are "lilioid monocots", i.e. their flowers superficially resemble those of the genus Lilium, with six tepals not differentiated into sepals and petals.

Various genera were constructed between 1837 and 1903 to divide up Zigadenus, including Amianthium (Gray, 1837), Anticlea (Kunth, 1843) and Toxicoscordion (Rydberg, 1903).

Only the first of these gained broad acceptance in the 20th century (e.g. the Flora of North America recognizes only Amianthium and Zigadenus[3]).

A study in 2001 based on both nuclear and plastid gene sequences led to the conclusion that the broadly defined Zigadenus was polyphyletic; in particular the genera Schoenocaulon and Veratrum-Melanthium were nested inside it.

[1][4] The cladogram below shows phylogenetic relationships in the Tribe Melanthieae; shaded names represent nodes which contain species formerly placed in the broadly defined Zigadenus.

Like other species in the genus, it grows from bulbs and has flowers with relatively narrow tepals, in this case coloured white to green.

As of April 2012[update], the World Checklist of Selected Plant Families recognizes four species, found in the central and eastern United States.

[9] Their flowers differ from Veratrum by being arranged in more open and delicate-looking inflorescences and by having tepals which narrow at the base.

The precise number is unclear; two species were only discovered in 2008, and many occur only in remote regions of Mexico, where their montane forest habitat is under threat.

[11] As of April 2012[update], Stenanthium consists of three[12] or four species (depending on whether S. leimanthoides is recognized) found in the south eastern United States.

[1] Like the other species, Stenanthium gramineum (feather bells) grows from a slender bulb, and has inflorescences with a complex branching structure in which individual flowers have narrow tapering tepals.

They generally have quite large leaves and inflorescences in which individual flowers vary in colour from white to green, yellow or purple.