Photo by Clint Cook I’m trying to poison my botany students. Well, that’s what most of them think.

Every field trip I’ve been nibbling on the berries and buds we run across and inviting the students to do the same. Aghast, they expect me to keel over and waste away, but I’m still OK. In fact, some of them, after considerable encouragement, will also taste a new–found natural tidbit. Why would I be doing this? Well, the answer is quite simple: many times, the taste or smell (or both) of a given species can be indicative of its identity. Plants have plenty of characteristics that lend to their identification, and taste is one of them.

The mystery plant is an herb that grows just about everywhere in the US and can bloom any time of the year, even winter. It’s a member of the mustard family and shows a number of easily identifiable features. All the members of this family have their sepals and petals in fours. The petals are arranged in a cross–like affair, at right angles to each other, and one of the scientific names for the family…Cruciferae… means “cross–bearing.”

Partridge berry, Deer berry, Mitchella repens The fruits formed by family members are pods, either short or long. The family has been known since antiquity as an important food source, and indeed, this is the family that supplies us with cabbage, broccoli, turnips, kohlrabi, Brussels sprouts, rapini, watercress, horse–radish, and of course, for the sushi– lovers, wasabi.

In fact, it is said that all members of this family are edible and quite nutritious, featuring vitamins, antioxidants, and in several, it is thought, anti–tumor activity. What accounts for the sharp flavor of these plants are “mustard oils,” a series of sulfur– bearing compounds, which in nature are useful for dissuading attack by insects. The mustard family also offers sweet alyssum, candytuft, honesty, wallflower, and fragrant stocks. There are also a number of fairly nasty little weeds, such as yard cress, poor–man’s pepper, and shepherd’s purse.

Our mystery plant has a taproot and grows to about two feet tall with divided leaves up and down its branching stems. This species is native to the Mediterranean region but is now common (as a weed) all over the world, and it is thought to be a possible ancestor to the cultivated radish. Its petals are most often yellow, although sometimes white or pink. Its fruits are elongated pods, up to about 4” long, each topped by a narrow beak. The stems and leaves feature tiny, sharp, spine–like bristles. The flowers and buds make a nice addition to a salad, raw.

Answer to last week’s mystery plant

Dr. John Nelson is the curator of the USC Herbarium.

To learn more about the Herbarium, call him at

777–8196. His department also offers free plant identification.

www.herbarium.org