In full sun.
Indian milkweed. Asclepias eriocarpa
Apocynaceae . LOTS of plants in this one area near the beginning of the Fish Canyon Falls trail in San Gabriel Mountains.
Asclepias L. (1753), the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as the subfamily Asclepiadoideae of the dogbane family Apocynaceae.