Milk Vetch Milkvetch
is a perennial found throughout northern and
southwestern China and northern North America. It
is a perfect plant for cold, and arid to semi-arid
regions with poor or saline soils. It has a very
long tap root and can get water deep in the ground.
In China it is grown as fodder, green manure and
for soil conservation. Milk vetches are part of the
bean family (Fabaceae). In Latin, fab means
"bean". Each plant
has a couple of stems that can grow to be 1.5 to 2
m tall. The leaves are each composed of 9 to 19
narrow leaflets, and are about 2 to 4 inches long
with soft hair all over them. The main tap root is
thick and has many roots growing off it. A
secondary root system starts about 20 Milkvetch flowers thoughout August. The lavender or bluish-purple flowers are about 1/2 inch long and arranged in a dense cluster. The cluster grows on a short stalk and can be cylindrical and about 3 inches long. Seeds grow in a small, hairy pods that turn black. The seeds are small and black and sometimes rattle in the pod, giving some species of this plant the name Rattle Pod. One species of Astragalus, Astragalus lentiginosus, contain the alkaloid swainsonine, which can cause locoism. When animals eat this astragalus their nervous systems become impaired, and they become very excited when disturbed. Sometimes they died. In the old days it used to be known as "loco weed". A less deadly variety of vetch can be found growing along our country's highways as soil erosion control. In the spring the blue flowers of vetch will carpet the sides of roads from New Enland to California. 2000
bibliography: "Astragalus adsurgens (Lavender Milk-vetch)", http://www.npwrc.usgs.gov/resource/literatr/wildflwr/species/astradsu. htm |