Plants and Animals
Dalea purpurea Purple prairie clover
Key Characteristics
Perennial forb of dry to dry-mesic prairies and savannas; leaves pinnately divided with 3-5 narrow, inrolled leaflets; flowers purple, in cone-like clusters borne on the ends of the stem.
Status and Rank
US Status: No Status/Not Listed
State Status: X - Presumed extirpated (legally 'threatened' if rediscovered)
Global Rank: G5 - Secure
State Rank: SX - Presumed extirpated
Occurrences
| County | Number of Occurrences | Year Last Observed |
|---|---|---|
| Lapeer | 1 | 1977 |
| St. Clair | 1 | 1915 |
| Van Buren | 1 | 1986 |
Information is summarized from MNFI's database of rare species and community occurrences. Data may not reflect true distribution since much of the state has not been thoroughly surveyed.
Habitat
Michigan's colonies were known from dry to dry-mesic, open sites with a history of natural and artificial disturbance.
Natural Community Types
For each species, lists of natural communities were derived from review of the nearly 6,500 element occurrences in the MNFI database, in addition to herbarium label data for some taxa. In most cases, at least one specimen record exists for each listed natural community. For certain taxa, especially poorly collected or extirpated species of prairie and savanna habitats, natural community lists were derived from inferences from collection sites and habitat preferences in immediately adjacent states (particularly Indiana and Illinois). Natural communities are not listed for those species documented only from altered or ruderal habitats in Michigan, especially for taxa that occur in a variety of habitats outside of the state.
Natural communities are not listed in order of frequency of occurrence, but are rather derived from the full set of natural communities, organized by Ecological Group. In many cases, the general habitat descriptions should provide greater clarity and direction to the surveyor. In future versions of the Rare Species Explorer, we hope to incorporate natural community fidelity ranks for each taxon.
Associated Plants
Virtually no data are available for Michigan. In Illinois this species occurs with such plants as little bluestem, leadplant, prairie cinquefoil, side-oats grama grass, needle grass, western silvery aster, furrowed flax, prairie smoke, and kitten-tails.
Management Recommendations
This prairie species may yet persist in Michigan, and thus status surveys are warranted. Management would require maintenance of open, dry prairie habitat through the use of prescribed fire.
Survey Methods
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.
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Meander search
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Survey Period: From fourth week of July to fourth week of August
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References
Survey References
- Elzinga, C.L., D.W. Salzer, and J.W. Willoughby. 1998. Measuring and Monitoring Plant Populations. The Nature Conservancy and Bureau of Land Management, Denver. BLM Technical Reference 1730-1. 477pp.
- Goff, G.F., G.A. Dawson, and J.J. Rochow. 1982. Site examination for Threatened and Endangered plant species. Environmental Management 6(4): 307-316
- Nelson, J.R. 1984. Rare Plant Field Survey Guidelines. In: J.P. Smith and R. York. Inventory of rare and endangered vascular plants of California. 3rd Ed. California Native Plant Society, Berkeley. 174pp.
- Nelson, J.R. 1986. Rare Plant Surveys: Techniques For Impact Assessment. Natural Areas Journal 5(3):18-30.
- Nelson, J.R. 1987. Rare Plant Surveys: Techniques for Impact Assessment. In: Conservation and management of rare and endangered plants. Ed. T.S. Elias. California Native Plant Society, Sacramento. 8pp.
Technical References
- Gleason, H. A., and A. Cronquist. 1991. Manual of Vascular Plants of Northeastern United States and Adjacent Canada. Second edition. The New York Botanical Garden, Bronx. 910pp.
- Gray, A. 1950. Gray's Manual of Botany; eighth ed. Van Nostrand Reinghold, New York. 1632pp.
- Holmgren, N.H. 1998. Illustrated Companion to Gleason and Cronquist's Manual. Illustrations of the vascular plants of Northeastern United States and adjacent Canada. New York Botanical Garden, Bronx. 937pp.
- Mohlenbrock, R.H. 1986. Guide to the Vascular Flora of Illinois. Southern Illinois University Press, Carbondale. 507pp.
- Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp.
- Voss, E. G. 1985. Michigan Flora. Part II. Dicots (Saururaceae-Cornaceae). Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 724pp.