Asclepias viridis is a species of flowering plant in the dogbane family known by the common names green antelopehorn and spider milkweed. It is native to the southcentral and southeastern United States. This milkweed is a perennial herb with alternately arranged leaves. The inflorescence is an umbel of white flowers with purplish centers. This species grows on many types of soil. It is common in overgrazed pasture land and roadsides. This, like some other milkweed species, is a host plant for the monarch butterfly.