Sarcostemma hirtellum (=Funastrum hirtellum) (Rambling Milkweed, Hairy milkweed), is a perennial, vine-like plant of mid- to lower-elevation desert regions in the Asclepiadaceae family, and the Sarcostemma genus, the climbing milkweeds. It is found in the southwestern United States and Northwestern Mexico, in the states of southeastern California, southern Nevada, Arizona, Sonora, and Baja California.
Hairy milkweed can be an aggressive opportunistic species that can overtake a suitable sprouting location and kill the plants it grows upon. If the supporting plants can compete successfully, all the species continue.
The green vines have few narrow leaves, and are themselves photosynthetic. In early- and mid-spring, flower clusters occur in a circular or half-globe cluster of 7 to 13+ florets, each floret about 3/8 in. The flower clusters are sometimes profuse, and therefore noticeable. When the dried seedpods remain months later, after the vines have desiccated, the pods are then the plant identifier. When the supporting species-(or multiple species) is being inundated by quantities of vines, that also becomes the indicator of the plants presence.