This section is from the book "A Manual Of Weeds", by Ada E. Georgia. Also available from Amazon: A Manual Of Weeds.
Native. Perennial. Propagates by seeds and by bulbs. Time of bloom: May to June. Seed-time: June to July. Range: South Dakota to British Columbia, southward to Nebraska, Utah, and California. Habitat: Shallow ravines, sides of foothills, upland pastures.
Western stockmen, particularly the sheep growers of Wyoming and Montana, owe to this plant a loss of many thousands of dollars yearly. All parts of it are poisonous to all grazing animals, but cattle usually reject it because of its bitter taste; horses are even more particular; but sheep feed with little discrimination and are, besides, the stock most commonly kept on the high benchlands and foothills where the plant is most abundant. (Fig 41.)
It springs from an elongated, ovoid, coated bulb, a half-inch or less in thickness, the stems six to twenty inches tall, slender and upright. Leaves very narrow and grass-like, deep green, with roughened margins and midrib, usually partly folded and with sheathing base. Flowers greenish or yellowish white, in narrow simple racemes three to six inches long, each pedicel subtended by a thin, lance-like bract; each blossom is about a half-inch broad, its six perianth segments triangulate ovate or elliptic and narrowing abruptly to a short claw, on the upper side of which is an irregular roundish gland; stamens six. The racemes lengthen as the fruits form and the erect capsules are longer than the segments of the perianth, which are persistent; capsules three-lobed and three-celled, each cavity containing a number of oblong angled seeds. After the fruits mature the plants wither, dying down to the bulbs early in July.
Fig. 41. -Death Camas (Zygadenus venenosus). X 1/ 3.
Herding of animals away from the plants while they are in the growing, succulent stage seems to be the only plan practicable on the open range. In more restricted localities the weed may be destroyed by putting the land under cultivation for a time. The bulb is easily and quickly pulled from the ground when it is softened by rains, and for small areas even the expense of removal by hand labor might well be afforded in order to cleanse the soil from such a dangerous plague.