About Asclepias hirtella (Pennell) Woodson
Asclepias hirtella (Pennell) Woodson is a tall perennial plant that grows up to 3 feet in height. It produces many narrow, linear leaves arranged alternately along its stem. Its flowers grow in lateral umbels attached to slender peduncles. Each stem can hold between 2 and 10 umbels, and each umbel can contain between 30 and 100 individual flowers. The flowers do not have horns, and range in color from greenish to slightly purplish. This species flowers from June through August. Asclepias hirtella closely resembles Asclepias longifolia, and is occasionally classified as a subspecies of A. longifolia. Asclepias longifolia is restricted to the Southeastern Coastal Plain, and differs from A. hirtella by having fewer and smaller flower umbels, and glabrous leaves. Asclepias hirtella grows in a variety of open habitats, including areas with dry sandy soil, prairies, and limestone glades. It can tolerate both wet and dry conditions, and prefers open habitats with full sun. It is a component of high-quality grassland communities, though it can also grow in disturbed conditions. It is considered uncommon across most of its range. Asclepias hirtella is native to an area ranging from West Virginia, Ohio, Michigan, and Wisconsin west to northern Iowa, Kansas, and Oklahoma, and south to southwestern Kentucky. It is a prairie species native to 13 US states and one Canadian province, but is becoming rare and declining in numbers across parts of its native range. In Minnesota, A. hirtella is rare and listed as a threatened species; within the state, it grows in mesic prairie habitats in the southeastern corner.
