Scarification: Soak in water, let stand in water for 24 hours
Stratification: cold stratify for 30-60 days
Germination: sow seed 1/4" deep, tamp the soil, mulch the seed bed
Asclepias cordifolia, also known as heart-leaf milkweed or purple milkweed, is a species of milkweed native to the western United States. It can be found in California, Nevada, and Oregon, growing at elevations between 50 to 2,000 meters. This perennial plant is valued for its stems by the Native American Miwok tribe, who dried and processed them into string and rope.
Heart-leaf milkweed is a beautiful plant that grows to a height of 0.3 to 0.6 meters. It features dark red-purple flowers with slightly elevated hoods above the base of the corolla. The unique flower structure consists of five fused stamens, circular attachments known as 'hoods', and an anther head surrounding the large stigma at the flower's center. The plant's large opposite leaves are heart-shaped, hence its name 'cordifolia', which means 'heart-leaved' in Latin.
This milkweed species is commonly found in open or shaded woodlands, often on rocky slopes and in mixed coniferous forests. It blooms from May to July and is known for the milky sap that exudes from its stem, which gives milkweeds their name.
Heart-leaf milkweed is an important plant for Monarch butterflies, as their caterpillars can often be found on it. Even after the caterpillar metamorphoses into a butterfly, it retains the alkaloids from the plant, which makes it unpalatable to predators.
In addition to its ecological significance, heart-leaf milkweed has various traditional uses. The Miwok tribe used it to make string, rope, and other cordage. The stems were harvested in the summer and dried, then combed to extract the fiber. The fiber was wound into balls for storage and later processing. This plant was also used as a contraceptive and snakebite remedy, although it should be noted that improper preparation can be toxic.
Overall, Asclepias cordifolia is a beautiful and fascinating species of milkweed that has played an important role in Native American cultures and provides crucial habitat and food for butterflies. Consider adding this plant to your garden to attract these vibrant pollinators and enjoy its unique beauty.