Monarch butterflies, which belong to the Nymphalidae family, seek out a single species of plant to lay their eggs and harbor and feed their larvae. The milkweed family of plants, known botanically as Asclepiadaceae, is their preferred habitat. These are perennial herbs that flower and there are nearly 200 species of milkweed, 27 of which grow in North America and are favored by monarch butterflies.
Asclepia syriaca blooms in a dull purplish pink and greenish-white mottled coloration in the praire, pastures, wastelands and flood plains of Southern Canada, North Dakota, Maine down to North Carolina and west to Oklahoma and Texas.
Asclepias purpurascens is a deep red flowering cultivar that grows in open deciduous woodlands of the Great Plains states and on the East Coast from North Carolina to Connecticut.
Asclepias amplexicaulis is a green and purple flowering cultivar that grows in sandy soils and is found primarily in the great plains states, Texas and New Mexico.