About Vicia hirsuta (L.) Gray
Vicia hirsuta (L.) Gray is an annual herb with a slender, often four-sided climbing stem that ranges from hairless to lightly hairy. The stem typically grows 70 to 90 centimeters tall, and can sometimes grow well over one meter. Its leaves are tipped with tendrils that help the plant climb, and each leaf holds up to 10 pairs of elongated leaflets. Each leaflet can reach up to 2 centimeters in length, and may have notched, flat, sharply pointed, or toothed tips. The inflorescence is a raceme that carries up to 8 flowers; these flowers grow near the stem tip, and often grow only on one side of the raceme. Each flower is whitish or pale blue, measures just a few millimeters long, and is short-lived. The fruit is a legume pod that grows up to 1 centimeter long and half a centimeter wide. The pod is hairy, often densely hairy, and ranges in color from pale green to nearly black. It usually contains two seeds. This species is native to Europe and Western Asia, and is found as an introduced species on other continents. In North American farms, hairy vetch is commonly used for cover crops and green manures. Typically, either common vetch or hairy vetch provides the leguminous portion of this cover crop, which is usually mixed with a grassy nurse crop such as rye or winter wheat to add more cellulose to the resulting organic matter. Note that the species Vicia villosa is also called hairy vetch.
