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.
The plant, like many others, is an introduced one. It is present in serious quantities only in the eastern provinces and states, but is found also in British Columbia and California. It grows one to two feet high, with a few widely spreading branches quite low on the stem. The pale, yellowish green leaves are deeply lobed and provided with a few stiff bristles. The flowers are fewer and larger than those of Wild Mustard and are conspicuously veined. The pods are swollen and jointed, with partitions between the seeds. When ripe, the pod breaks at the joints, and the seeds are shed, each enclosed in its own portion of pod.
The seed itself is about one-eighth of an inch long, oval, irregular, and slightly flattened. It may, however, vary greatly in size and shape. The finely netted surface is reddish brown in colour.
Fig. 26. - Seeds and broken pods of Wild Radish - Raphanus Raphanistrum. Five times natural size.