Smooth camas is also known by other common names, the most familiar being swamp-camas, cow-grass, green lily.
It is a much more attractive plant than the death camas. It grows to a height of one to three feet, with much larger flowers and leaves. The leaves, stalks, and bracts are of a whitish-green colour, the bracts sometimes tinged with red or purple. The flowers are greenish white or cream coloured, from one-half inch to nearly one inch broad. The perianth leaves are six, each with a large, green, heart-shaped gland at the base. The stamens are also six, their stalks erect about the ovary and the three stigmas. The flowers are in bloom about two weeks later than death camas.
Phtoto - F. Fyles.
Smooth camas is more confined to wet ground and calcareous soils. It is widely distributed, occurring from New Brunswick and Quebec to Manitoba and westward to British Columbia and the Yukon.
Apparently all species of zygadenus are poisonous to animals, and contain the same poisonous alkaloid zygadenine. There is not, however, the same likelihood of serious loss among sheep, as smooth camas does not grow so abundantly in any one area and its period of growth is somewhat later in the season, when other herbage is prevalent and more tempting.
According to Marsh and Clawson, cases of poisoning have occurred among children who have eaten the bulbs in mistake for those of the edible camas, i. e. species of Calochortus and Camassia.