Sarcostemma hirtellum (Funastrum hirtellum) (rambling milkweed, hairy milkweed), is a perennial, vine-like plant of mid- to lower-elevation desert regions. It is a member of the Asclepiadaceae family, and the Sarcostemma genus, the climbing milkweeds. It is found in the southwestern United States and northwestern Mexico - in southeastern California, southern Nevada, Arizona, Sonora, and Baja California. Hairy milkweed can be an aggressive, opportunistic species, capable of overtaking a suitable sprouting location and killing the plants it grows upon. If the supporting plants can compete successfully, all of the species continue.