purple blooms on American vetch plant

American Vetch flowers

American Vetch plants are early purple blooms among the grasses out in the Willow Spring Open Space. The blooms start in April- May and continue through August. The purple blossoms are shaped like a butterfly with 5 petals. American Vetches have tendrils at the end of their stem which they wrap around other plants or structures to hold their weight while climbing.

These plants are perennial herbs, which means that the plant does not die in the winter, although it may go dormant. The spring growth is from the roots of the existing plant.

The plants are erect, though with weak stems, and can be a height of 6-20″. This is a native plant to Colorado, common throughout the state in meadows, along streams, in aspen forests and on the shortgrass prairie.

Their leaves are composed of 8-16 long narrow leaflets along a stem that are arranged like two combs stuck back to back (referred to as a pinnate leaf).

Scientific Name and Plant Family Information

The Scientific name for the American Vetch plant is Vicia americana Muhl. ex Willd. Vicia is from the Latin – related to vincire “to bind” which relates to how these plants climb with tendrils. Vetch is the English word for Vicia. Americana refers to this plant being in America. “Muhl. ex Willd.” refers to the scientists that named the plant. Gotthilf Henry Ernest Muhlenberg first named the plant; the ex means that it was not validly published, and Carl Ludwig Willdenow validly published the name.

It is in the plant family Fabaceae (pea), which also includes peas, beans, peanuts, alfalfa and honey locust trees. Many plants in this family are also referred to as legumes.

Plants in this family have distinctive 5-petal flower heads. They are made up of 5 petals: 1 large banner petal in the back, 2 wing petals and 2 central keel petals which are usually fused together. Most also have pinnate leaves (a stem with leaflets on either side of the stem). Pea family plants also are known for distinctive pea-like pods.

Most peas are known as “nitrogen-fixing” plants, that is they add nitrogen to the soil when they decompose. That is very beneficial for growing other plants in that soil.

The Pea plant family is the third largest family of flowering plants in the world (after Orchids and Sunflowers).

purple pea flower among grasses
American vetch

Through the Seasons

The American Vetch plants start blooming in May and end in August.

Native or Non-Native?

American Vetch is native to all of Colorado. There are 2 varieties. One is more common in meadows, along streams and in aspen forests 4,800 to 10,500 feet elevation, and the other variety is found in meadows and on the shortgrass prairie of the eastern plains 3,900 to 8,500 feet elevation.

Where to find in Willow Spring Open Space

These American Vetch blooms were spotted along the south end of the trail, near Homestead Elementary school.

Did You Know?

American Vetches are closely related to sweet peas, lentils and the garden peas. The seeds and young stems of American Vetches are edible, although the plants may contain cyanide, so best not to eat them raw, or at all!

References and Further Reading