Planting the most popular things will get you lots of butterflies; planting the specifics will help save rare butterflies. The more diverse the habitat, the more butterflies it attracts. Here at Fieldhaven we have many different types of trees and bushes, herb gardens, flower gardens, the prairie garden, and so on. My definition of "lawn" is "whatever low-growing green stuff survives mowing and foot traffic." It includes a wide variety of grasses along with clover, dandelions, violets, and assorted weeds. When choosing plants to buy for a wildlife garden, make sure the seeds or seedlings have not been treated with insecticides. Shop organic if possible and look for pollinator-friendly suppliers.
Among the host plants I have: wild cherry, willow, plum, oak, hackberry, hawthorn, serviceberry, milkweed, butterfly weed, mayapple, violet, black-eyed susan, sunflower, beardtongue, thistle, aster, cup plant, compass plant, goldenrod, plaintain.
Butterflies I see around here: black swallowtail, tiger swallowtail, clouded sulphur, eastern tailed-blue, monarch, silvery checkerspot, mourning cloak, painted lady, red admiral, common buckeye.
What do you have in your area?