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Plant of the Week

Map of the United States showing states. States are colored green where the species may be found. Range map of scarlet milkvetch. Map from USDA PLANTS Database.

Scarlet milkvetch in flower. Scarlet milkvetch in flower. Photo by Sue Weis, Inyo National Forest Botanist.

Scarlet Milkvetch (Astragalus coccineus Brandeg.)

By Forest Jay Gauna

Astragalus is a very large genus of the legume family (Fabaceae). Another name is “milkvetch,” which is said to be the designation for less poisonous (or rather, less immediately poisonous) species. The generic name, Astragalus, is a Greek word for the anklebone, which probably refers in some way to the fruits (pods). Coccineus simply means “scarlet” or “bright red,” referring to the bright red flowers. Vetch is another plant of the legume family (Vicia). The name was applied to milkvetch because of its compound leaves and the similar appearance of the inflorescences.

“Locoweed” derives from the effects of some Astragalus spp. upon livestock, poisoning their minds and nervous systems so that they seem to go crazy, or loco. Although some sources say that Native Americans utilized certain Astragalus species, we emphatically advise that people see their flowers or inflated pods and then leave them alone, lest they try to use them somehow and become muerto (dead).

Recognizing Astragalus species can be a bother even for botanists. There are about 2,000 species worldwide, and the differences between them are often not easy to see. If looking for this plant, the easiest method is to be in east-central California, southwestern Nevada, or northwestern Arizona; this habitat should be replete with sagebrush and/or piñon trees. In the gravelly soil, from March through June, look for scarlet flowers. Upon close inspection, the flowers should have a familiar legume flower anatomy: bilateral, with the petal on top bent back (the "banner"), and two fused petals on the bottom forming a “keel”. The leaves are separated into several leaflets, and are fuzzy.

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