Milkweed is the host plant used by the Monarch butterfly.
The common milkweed bears clusters of dull purple flowers with a heavy cloying odor which, though unpleasant to us, is unusually attractive to bees and butterflies. Each flower of the cluster has an elaborate trap to catch the legs of these insects and remove any pollen they may carry. Sometimes the insect cannot escape and pays with its life for the nectar it came to drink. Indians produced sugar by shaking the honeydew from its blooms in early morning and drying it.

Each cluster of blossoms is followed by one or two large warty pods with a seam along one side which pops open when the pod becomes ripe and dry. Inside is a closely packed roll of several hundred flat brown seeds arranged like scales on a fish, each with a folded parachute of fine silky fibers. Gradually, these parachutes open and the seeds are carried away on the fall winds. During the war, hundreds of tons of milkweed pods were gathered by school children and the silky fluff processed as a substitute for kapok, used to pad life jackets and flying suits.

The Butterfly Weed or Pleurisy Root with its glowing orange flowers is the most beautiful of the milkweeds. Unlike other milkweeds, it lacks the milky juice. The Indians used its roots for medicine and cooked the green pods with their buffalo meat much as we use green peppers. The Swamp Milkweed bears masses of brilliant red or rose-purple flowers which are followed by pencil-slender pods. The dainty Whorled Milkweed has tiny greenish white flowers and very slender leaves. Mixed with hay crops it can be poisonous to livestock.
Milkweeds As Medicine
The generic name Asclepias honors Asklepios, the Greek god of medicine, so highly did Native Americans and ­European settlers value milkweeds as medicine. Millspaugh (who apparently was enamored of the genus) summed up the manifold uses of one species, A. tuberosa, known to gardeners as butterfly weed but to herbalists as pleurisy root:

The pleurisy root has received more attention as a medicine than any other species of this genus, having been regarded almost since the ­discovery of this country as subtonic, diaphoretic, alterative, expectorant, diuretic, laxative, escharotic, carmin­ative, anti-spasmodic, anti-pleuritic, stomachic, astringent, anti-rheumatic, anti-syphilitic, and what not.

I don't know what half these terms mean, but I, too, am impressed. This species was listed in the U.S. Phar­macopoeia as late as 1936.

Several species are still used medicinally by herbalists. The latex from showy milkweed (A. speciosa) and common milkweed (A. syriaca) is used as a treatment for warts, ringworm, and other skin ailments. Root extracts of pleurisy root are used for respiratory disorders and those of common and swamp milkweed (A. incarnata), for intestinal parasites. Paralleling this latter use, the U.S. Depart­ment of Agricul­ture is currently investigating the nematode-fighting properties of ground milkweed seeds. Some­day, gardeners and farmers may be able to add them to their arsenal of natural nematocides.

Milkweeds As Food
Several milkweeds have been traditional Native American foods. When properly prepared by repeated blanching to remove the bitterness, tender young shoots, leaves, flower buds, and seedpods of common and showy milkweeds are edible, even tasty. To be on the safe side, avoid the other species, which may be or are known to be more toxic. Choose shoots no longer than 6 inches, leaves that have just opened, flower buds that look like loose heads of broccoli, and seedpods that are no more than 2 inches long. Place the parts to be eaten in a large pot and cover with boiling water; boil for one to two minutes and drain. Repeat these steps three more times (failure to use boiling water can set the bitterness ­instead of removing it). Then cook the vegetables until they are tender and serve with lemon and butter, or stir-fry with olive oil and other vegetables. The pods
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