ARS | Publication request: AN EVALUATION OF POLLINATION MECHANISMS FOR PURPLE PRAIRIE-CLOVER, DALEA PURPUREA (FABACEAE: AMORPHEAE)

Submitted to: American Midland Naturalist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 20, 2006
Publication Date: July 1, 2006
Citation: Cane, J.H. 2006. An evaluation of pollination mechanisms for purple prairie-clover, Dalea purpurea (Fabaceae: Amorpheae). American Midland Naturalist. 156:193-197.

Interpretive Summary: The perennial wildflower purple prairie-clover represents a large genus of New World legumes that are common in prairies, deserts and adjacent biomes. Its breeding biology was studied experimentally, anticipating agricultural seed production of several of these species for use in wildland rehabilitation and revegetation. Pollinator visits are required for seed set, with outcrossing nearly doubling the seed production of selfing. More than 50 native bee species visit its flowers in the wild. From among these or several managed species, effective and manageable pollinators can be expected. Use of prairie-clovers in restoration seed mixes will benefit native bee communities and the other wildflowers that they pollinate.

Technical Abstract: Purple prairie-clover (Dalea purpurea Ventenat) is a common perennial forb that flowers during mid-summer throughout the Great Plains and adjacent biomes. Its seed is desirable for use in prairie restoration. The objective of this study was to evaluate the breeding biology of D. purpurea. Manual pollination field trials showed that D. purpurea has a mixed pollination system. It is primarily xenogamous (45% of manually pollinated flowers yielded plump seeds) but partially self-compatible (19% of selfed flowers yielded seeds). Flowers that were not visited or manually pollinated rarely yielded mature seed (0-6% of flowers). A review of extensive bee community surveys conducted at sites containing a diverse prairie wildflowers revealed that D. purpurea attracts a rich and diverse native bee fauna, which bodes well both for its pollination in small commercial seed fields as well as for its value for sustaining native pollinator faunas in prairie restoration efforts.