|Creeping St. John's-wort|
Photo by Brad Slaughter
Small rhizomatous forb (40-80 cm) of coastal plain marshes; leaves in whorls, narrowly elliptic to lanceolate and revolute, pinnately veined, 3.5-7 cm long; flowers 1-2 cm wide, yellow, in terminal clusters, sepals revolute.
Status and Rank
- State Status: T - Threatened (legally protected)
- State Rank: S1 - Critically imperiled
- Global Rank: G3 - Vulnerable
|County Name||Number of Occurrences||Year Last Observed|
Updated 05/08/2013. 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.
First collected in Michigan in 2005, this species is known only from the margins of coastal plain marshes.
Natural Community Types
Bluejoint grass, prairie cordgrass, panic grass, wool-grass, three-way sedge, wire sedge, black-fruited spikerush, tall beak-rush, Canadian rush, hyssop hedge-nettle, lance-leaved violet, meadow-beauty, grass-leaved arrowhead, northern bugleweed, fireweed, Canadian St. John's-wort, larger Canadian St. John's-wort, lakes flat-topped goldenrod, southern blue flag, swamp dewberry, meadowsweet, and steeplebush.
This species requires conservation of habitat and protection of the hydrology, including maintenance of cyclical drawdown regime and water table. Maintain moist, open habitat. It is also vulnerable to ORV impacts and dredging and filling activities.
General Survey Guidelines
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.
- Meander search
Survey Period: From fourth week of June to first week of October
- 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.
- 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.