Of the seventeen milkweed plants (Asclepias genus) that are native to Iowa, only five are widespread in our state: common milkweed, swamp milkweed, butterfly milkweed, whorled milkweed, and sand milkweed.
Today’s featured plant, Tall green milkweed (Asclepias hirtella), is considered “scarce” rather than endangered or threatened in Iowa. Its native range includes parts of eighteen states from the Gulf of Mexico to the Great Lakes, plus the Canadian province of Ontario. According to the Illinois Wildflowers website, preferred habitats have exposure to full sun, with “moist to dry conditions, and sandy or gravelly soil,” including “dry-mesic railroad prairies, sand prairies, rocky glades, edges of sandy wetlands, roadsides, pastures, and abandoned fields.” This species is sometimes known as prairie milkweed.
Tall green milkweed plants typically reach a height between one and three feet, so aren’t particularly tall compared to some summer wildflowers on the prairie, such as compass plant or cup plant. But it’s taller than a related species called green milkweed ( Asclepias viridiflora). The Minnesota Wildflowers site advises that flowers of Asclepias hirtella “are different enough to avoid confusion, plus A. viridiflora is typically a shorter plant with less densely packed leaves.”
I’ve never seen tall green milkweed in the wild, so relied on other photographers for all of the images enclosed below.