Milkweed is the name of more than 100 kinds of plants that have silky, hairlike tufts on the seeds and contain a milky juice. The common milkweed is one of the best-known milkweeds in North America. It grows along roadsides and in fields and waste places in the eastern United States as far south as Georgia.
The stems of the common milkweed stand from about 31/4 to 61/2 feet (1 to 2 meters) high and bear large, hairy, pale green leaves on short stalks. The purplish flowers grow in clusters at the tip of the stem. The flowers bloom from June to August and have a sweet odor that attracts insects. Each flower is shaped so that an insect has to walk through masses of pollen before it reaches the nectar. The insect then flies away with two bundles of pollen on its legs and brings about cross-pollination when it visits another milkweed of the same kind (see Pollen (Cross-pollination) ).
By autumn, large, rough seed pods have developed from the flowers of the milkweed. When the pods ripen and burst open, clouds of seeds are scattered by the wind. The milkweed can also reproduce itself from its creeping, underground roots. In 1942, milkweed floss was collected as a wartime substitute for the kapok fiber used in life belts. The milky juice of the milkweed contains small amounts of a rubberlike substance. One of the most attractive milkweeds is the butterfly weed.
