Asclepiadaceae : Asclepias pumila
Family Name
Asclepiadaceae
Common Name
Plains milkweed
Native American Name
Lakota: čhešlóšlo pȟežúta,
Description
Asclepias pumila is a perennial herb with milky white sap, which grows from a taproot or slender rhizome with 1 to several stems arising from a branched base and reaching 8 cm to 30 cm in height. The leaves are simple, alternate in a tight spiral and often whorled near the base of the stem. The blade is narrow 1.5-6 cm long and about 1 mm wide, erect to spreading, lacks a petiole and the margin is entire. There are 1 to many inflorescences in the axils of the upper leaves, each with 4-20 flowers in an umbellate cyme. The flowers are 5-8 mm long, the calyx green to purple with 5 lobes. The corolla is white to pink tinged or sometimes a yellow green, reflexed and 2.8-4.2 mm long. The fruit are follicles that are erect, narrow cylinders 4-6 cm long and 6-8 mm wide. The seeds are ovate 4-6 mm long with long white hairs that turn brown with age. As with other milkweeds the stamens and pistils are fused, greenish-white and 0.6 to1.1 mm tall. Plains milkweed blooms from July to September in prairies and along hillsides throughout South Dakota.
Horticulture Notes
Seed Collection: Collect seeds when the pods turn brownish and begin to open in the late fall or early winter.
Germination: Seeds require a moist cold treatment before germinating. Planting out in the fall or 30 days in moist soil in the refrigerator will allow them to grow.
Vegetative Propagation: established plants can be subdivided in the spring.
Soils: Tolerate a wide range of soils but prefers a well-drained sandy loam.
Light: Full sun.
Water: medium to dry conditions.
Additional Notes
Plains milkweed is an attractive addition to native plant gardens, small and spreading slowly’ Its foliage is used by monarch butterflies and its flowers attract bumblebees and several types of butterflies.