Asclepias texana (Texas Milkweed)

Native to Texas, United States and northeastern Mexico, this perennial herb develops a slightly woody base and grows about 2 feet tall. In Texas, it grows in moist canyons, often among limestone hills, and flowers from May through August. Its small white flowers grow in clusters, and its leaves feed monarch caterpillars. Milkweed pollen travels in compact packets that visiting insects carry between flowers. The seeds have silky tufts that help them disperse on the wind. Its milky sap contains toxic cardiac glycosides. Photographed in Virginia, United States.