Oral and gastrointestinal irritation, photosensitivity, breathing difficulty. Mustard family members have a pungent, sulfurous odor or taste. They may be annual, perennial, or biennial, with a basal cluster of leaves and alternate leaves on the stem that are usually smaller and shorter-stalked than the basal leaves. These are found in fields, pastures, lawns, roadsides, waste areas, and sometimes in woods. Cultivated mustards, which may be harmful if eaten in large quantities, include cabbage, rape, broccoli, turnip, rutabaga, horseradish, and radish.
Mustard plants are capable of causing several types of problems.
The most common is oral and gastrointestinal irritation primarily the result of the isoallyl thiocyanates and irritant oils. The plants are not palatable and tend to be avoided unless there is little else to eat or if the seeds have been incorporated into processed feeds. In order to cause toxicity, fairly large amounts need to be consumed over a period of time. Mustard plants can cause other problems, although these are not reported as often. There are also reports of abortions, goiter and blindness due to mustard consumption, but these are not major problems.