Synonyms: Asclepias giffordii A perennial, coarser than A. tuberosa, plants densely white tomentose, large pink clusters of flowers appearing from June to August. Pods are 3.5-4.5 inches long and are covered with white hairs. Rhizomatous, may be aggressive. Found from Manitoba to MN, TX, west to B.C. and CA. Common along roadsides, fields, streamsides and other moist sites. Best in full sun, moderate to moist sites, considered a wetland species; excellent for butterflies, can be aggressive.