This section is from the book "A Guide To The Poisonous Plants And Weed Seeds Of Canada And The Northern United States", by Robert Boyd Thomson, H. B. Sifton. Also available from Amazon: A guide to the poisonous plants and weed seeds of Canada and the northern United States.
Other Common Names: Cow Herb, China Cockle, Spring Cockle.
This plant is a close relative of Purple Cockle and was suspected of producing similar effects. Its growing prevalence in western grain fields led Ches-nut and Wilcox to investigate the truth of these suspicions. Their experiments with rabbits corroborated the earlier statement that the plant contains a poisonous, saponin-like substance, and established the fact that this poison is plentiful in the seed. A water extract of twenty-one grams of the seed, made a three-pound rabbit very ill, but it finally recovered. The residue from the water extraction was treated with 50% alcohol, and the solution from 1.5 grams of the seed, when injected into a thirty-two-ounce rabbit, caused death.
Symptoms and treatment follow the same lines as in the case of Purple Cockle. The use of the permanganate solution as described (p. 52) is recommended if the pre-sence of seeds in the stomach at the time of treatment is suspected.
Fig. 21. - Seeds of Cow Cockle - Saponaria Vaccaria. Five times natural size.
The plant is an annual, introduced in grain from southern Europe, and thrives among the spring wheat of the west, where it is spreading rapidly. Its stem, simple or branching, is one to two and one-half feet tall, smooth, succulent and greyish green. The broadly lance-shaped leaves have no petioles, their base clasping the stem. The flowers are in flat-topped racemes, pale pink, and one-half inch across.
The calyx is much inflated and five ribbed. The fruit capsules are smooth and similar to those of Purple Cockle but much more inflated, and contain about twenty seeds each.
The seeds are about one-twelfth of an inch across, round, hard and dull black. The surface is minutely roughened and there is a shallow groove down one side. On cutting the seed open the germ can be seen, curved about the outside of the starchy endosperm, just beneath the seed coat. When finely ground in feeds, it is only by careful microscopic examination that its presence can be determined.