Field penny-cress likes to live in cultivated fields and farmers heartily dislike it as it depletes the nutrients in the soil. However researchers in Illinois believe that it could be a biodiesel and animal fodder crop as its seeds have a high oil yield. This would help scientists in their search for biofuel which comes from a crop which is not a traditional food one, such as soy beans or maize.
Field pennycress is a native of Europe and was introduced to North America. They also grow in parts of North Africa and Asia. It grows to heights of between eight and sixteen inches (20-40 cms.) and has “winger” seed pods which are round and flattened. This is how it gets its genus name, Thlapsi which is the ancient Greek for “to crush.” Arvense means “of the fields” meaning fields used for crops. Field penny-cress cannot survive in areas of dense vegetation but adores tilled land.
It is a member of the Brassicaceae or Cruciferae family of plants making it a relation of mustard, savoy cabbage and others, kale, broccoli, cauliflower, watercress, swede, turnips, horseradish, kohlrabi, brussel sprouts, shepherd’s purse, scurvy-grass and flixweed to name but a few of its relations. Its leaves are high in protein and vitamin C, and they are said to taste like mustard and onions. In fact the ground seeds have been used as a mustard substitute.
It has been a notorious weed for centuries and one Finnish law dating from 1734 illustrates this. The law says “Let he who throws wild oats, field penny-cress, or any other weed into his neighbour’s field lose his honour and be fined…and pay compensation for damage.” This seems a steep penalty for such an action! Clearly field penny-cress was and is a particularly unpleasant weed.
Indeed, it has a rather unpleasant smell, according to some. However its leaves are edible but slightly bitter when young. These can be added to salads or used as a potherb or added to soups. When the plant comes into flower the leaves are very bitter and unpalatable though. They can also cause gastric problems, so beware.
The sprouted seed can be added to salads and contains an oil which was used in the past for lighting.
Other English names for this plant are fanweed, stinkweed and Mithradate mustard. It has been used for the treatment of carbuncles and internal ulcers too, as well as acute appendicitis, as a diaphoretic (promoting sweat in fevers), a diuretic, for rheumatism, as an expectorant, and for liver problems, kidney inflammation, as a blood purifier and an expectorant. It has been found to have antibacterial properties against some bacteria. However, large doses can decrease white blood cell count, so if you use it treat it with care and under the supervision of a physician.
Perhaps field pennywort will prove a good animal feed/biofuel crop and lose its negative reputation in the near future.