death camas

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. Any of several plants of the genus Zigadenus of western North America, having grasslike leaves and clusters of usually greenish-white flowers. All parts of the plant are poisonous to livestock.

Wiktionary

1. n. A member of a species of poisonous, perennial, flowering plants, Zigadenus venenosus, whose bulbs (rhizomes) look, but do not smell, like onion.
2. n. more generally A member of any of various similar species, also called star lilies, of family Melanthiaceae, and formerly grouped into the genus Zigadenus.

WordNet 3.0

1. n. any of various plants of the genus Zigadenus having glaucous leaves and terminal racemes of mostly white flowers; all are poisonous