Some can be started from bulbs, corns, rhizomes, stolons, or tubers. Also, the nursery industry needs though plants that survive transplanting, shipping, and other environmental changes. At the same time, the industry needs plants that can be produced on a commercial scale. Although out of print at USDA, Cathey's ARS booklet, Growing Flowering Perennials, Hong and Garden Bulletin No. 114, may be of interest to wildflower growers.
Some libraries still have it.
American Nurseryman Magazine. Directory to Resources on Wildflowers' Propagation. An information source on nursery industry research involving native plants is Dr. Richard E. Bir, Extension horticulture specialist at North Carolina State University. This nonprofit organization, financed entirely by contributions, has a membership of more than 8,000. 973 North, Austin, TX 78825.