Herbs, perennial, from bulbs; bulbs tunicate, ovoid-oblong, ca. 5 × 2.5 cm; roots contractile. Stems erect, simple. Leaves mostly basal, reduced distally, spiral, arching downward, sheathing proximally; blade linear-elongate, strap-shaped, glabrous, apex obtuse to abruptly acute. Inflorescences terminal, racemose, dense, bracteate, glabrous. Flowers bisexual or both bisexual and unisexual flowers borne on the same or on different plants, cup-shaped to widely spreading, pedicellate; tepals persistent, 6, distinct, white, turning reddish green, claws absent, oblong-obovate, equal to subequal, apex acute; tepal glands absent; stamens 6, perigynous, distinct; filaments subulate, apex acute; anthers basifixed, 1-locular, cordate-ovate, extrorse, opening into peltate disc (apical/valvate dehiscence); pollen sacs apically confluent; ovary superior to partly inferior, 3-locular, diverging; septal nectaries absent; styles persistent, 3, widely diverging, distinct; stigmas terminal, minute. Fruits capsular, deeply 3-lobed, thin-walled, dehiscence septicidal, then adaxially loculicidal. Seeds 1–2 per locule, brownish to purplish black, wingless, ellipsoid, lustrous; testa fleshy. x = 8.
e North America.
Amianthium is frequently included in a broadly circumscribed Zigadenus (J. D. Ambrose 1975, 1980; S. M. Kupchan et al. 1961; S. J. Preece 1956; W. B. Zomlefer 1997b). The absence of tepal nectaries or glands is a major generic characteristic of this Appalachian–Ozark taxon (F. H. Utech 1986). Narrow-leaved specimens of Amianthium are often confused with Zigadenus densus.
A self-incompatible, pollination-breeding system involving primarily beetles occurs in Amianthium (M. E. Palmer et al. 1989; A. M. Redmon et al. 1989; J. Travis 1984). An associated tepal color shift, as in Zigadenus densus, may represent possible pollinator signals (J. Travis 1984).
Two unique, toxic alkaloids, jervine and amianthine, found in Amianthium roots and leaves (N. Neuss 1953; S. M. Kupchan et al. 1961; R. F. Raffauf 1970; I. W. Southon and J. Buckingham 1989; G. E. Burrows and R. J. Tyrl 2001), caused deaths in cattle and sheep. Native Cherokee used the plant as a dermatological cure for itch and as a crow poison (D. E. Moerman 1986). Root extracts mixed with molasses or honey have been used as a housefly insecticide (C. D. Marsh et al. 1918).