death camas

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Any of several plants of the genus Zigadenus, primarily of North America, having grasslike leaves and clusters of usually greenish-white flowers. All parts of the plant are poisonous.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

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

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

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