Purple milkweed (Asclepias cordifolia) has an unusual flower. Five stamens (pollen producing organ) are fused into a column. The anthers surround the stigma (female sexual organ) at the flower center. And five peculiar attachments, called hoods, surround the stamen parts. The result is a beautiful, open inflorescence.
Like other milkweed species, the fruit is a flat achene (dry seed) topped by silky hairs. Dispersal is via the wind.
The common name, purple milkweed, derives from the purple stems, peduncles and flowers. The species name, cordifolia, means heart-shaped and refers to the opposite, waxy, blue-green, heart-shaped leaves. The leaf shape gives rise to another colloquial name for this plant, heart-leaf milkweed.
Purple milkweed is a native perennial that grows in the Sierra Cascade and Cascade Ranges of Oregon, California and Nevada. It can be found in open, shaded woodlands, on rocky slopes and in mixed coniferous forests.
Native Americans processed the stems of purple milkweed into string and rope. They also used small amounts as a contraceptive and snakebite remedy. Purple milkweed contains alkaloids in the sap that cause vomiting in small amounts and can cause death if large doses are ingested.
The monarch butterfly feeds on milkweeds and the alkaloids accumulate in its body making it poisonous to predators.
These purple milkweeds were growing near a parking area close to Crystal Lake (Shasta County CA). I think this is a beautiful plant.