| Asclepias purpurascens |
| Purple milkweed |
Key Characteristics
Perennial forb of moist prairies; leaves opposite on short petioles with dense short hairs below, tips acute; flowers purple, borne in 1-3 terminal clusters.
Status and Rank
- State Status: T - Threatened (legally protected)
- State Rank: S2 - Imperiled
- Global Rank: G5? - Secure (inexact)
Occurrences
| County Name | Number of Occurrences | Year Last Observed |
|---|---|---|
| Barry | 1 | 2006 |
| Berrien | 3 | 2006 |
| Cass | 2 | 2008 |
| Clinton | 1 | 1893 |
| Ingham | 1 | 1893 |
| Jackson | 6 | 2006 |
| Kalamazoo | 4 | 2008 |
| Lenawee | 2 | 1999 |
| Livingston | 2 | 1959 |
| Monroe | 1 | 1906 |
| Newaygo | 2 | 2009 |
| Oceana | 1 | 2006 |
| St. Clair | 2 | 2006 |
| St. Joseph | 1 | 1979 |
| Van Buren | 5 | 2008 |
| Washtenaw | 3 | 2005 |
![Occurrence Map for [Sname]](/mnfi/maptmp/NFR_Distributions1259020254804.png)
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
Found in a variety of open prairie-like habitats including prairie fens, savannas, woodlands, and thickets with dry to wet soil.
Natural Community Types
Associated Plants
Bluejoint grass, cordgrass, rush, sedges, twig-rush, shrubby cinquefoil, swamp milkweed, big bluestem, Indian grass, Sullivant's milkweed, purple milkweed, swamp thistle, eastern prairie fringed orchid, marsh blazing star, whorled loosestrife, grass-of-Parnassus, smooth hedge nettle, swamp rose, Missouri ironweed, prairie dropseed, three-awn grass, ironweed, tall coreopsis, and creeping cinquefoil. In oak barrens, it may also be associated with black oak, white oak, bur oak, bitternut hickory, pignut hickory, shagbark hickory, leadplant, butterfly weed, little bluestem, and big bluestem.
Management
Maintain hydrological and natural disturbance regimes. This species most likely requires open conditions. Prevent woody plant encroachment by using prescribed fire or manual brush removal. Much of this habitat has been lost and degraded via conversion to agriculture, development, alterations of hydrology via drains, and fire suppression.
General Survey Guidelines
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.
Survey Methods
- Meander search
Survey Period: From fourth week of June to fourth week of August
More Information
See MNFI Species AbstractReferences
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
- Cooperrider, T.S. 1995. The Dicotyledonae of Ohio Part 2. Linaceae through Campanulaceae. Ohio State University Press, Columbus. 656pp.
- 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.
- Swink, F. and G. Wilhelm. 1994. Plants of the Chicago Region, 4th ed. Indiana Academy of Science, Indianapolis. 921pp.
- Voss, E.G. 1996. Michigan Flora. Part III. Dicots (Pyrolaceae-Compositae). Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 622pp.