About Funastrum hirtellum (A.Gray ex Brewer & S.Watson) Schltr.
Funastrum hirtellum, also known by the synonym Sarcostemma hirtellum and the common names rambling milkweed and hairy milkweed, is a perennial, vine-like plant that grows in mid- to lower-elevation desert regions. It belongs to the family Asclepiadaceae and the genus Funastrum. It occurs in the southwestern United States and northwestern Mexico, specifically in southeastern California, southern Nevada, Arizona, Sonora, and Baja California. Hairy milkweed can be an aggressive, opportunistic species, capable of overtaking a suitable sprouting spot and killing the plants it grows upon. If the supporting plants are able to compete successfully, all species will continue growing. The plant’s green vines bear few narrow leaves, and the vines themselves perform photosynthesis. In early and mid-spring, it produces flower clusters that form circular or half-globe shapes holding 7 to 13 or more florets; each floret is about 3/8 of an inch across. These flower clusters are sometimes profuse, making the plant easy to notice. Months after the vines have dried out, dried seedpods remain attached and act as a identifying feature of this plant. Another clear indicator of Funastrum hirtellum is the covering of one or more supporting species by large quantities of its vines.
