Plants and Animals
Prenanthes crepidinea Nodding rattlesnake-root
Large, perennial forb of southern floodplain forests; stem ranging from 1-2.5 m, arising from a basal rosette of stalked, coarsely-toothed leaves, with scattered, slightly reduced leaves upward; flowers terminal, with stalked, nodding, flower heads produced in a broad, non-cylindric inflorescence, the flower head bracts (involucre) coarsely hairy.
Status and Rank
State Status: T - Threatened (legally protected)
Global Rank: G4 - Apparently secure
State Rank: SNR - Not ranked
|County||Number of Occurrences||Year Last Observed|
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.
Known only from a single occurrence, a floodplain forest in southeastern Lower Michigan.
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.
American elm, hackberry, black maple, wingstem, purple Joe-pye-weed, and garlic mustard.
Little is known about this species in Michigan, but at the present time it is likely best conserved by maintaining floodplain habitat, including the protection of hydrology and seasonal flooding and drawdown cycles, the control of invasive plant species, and preventing the fragmentation of habitat and activities such as excessive timber removal or uncontrolled recreational use.
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.
Survey Period: From third week of May to fourth week of August
- 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.
- 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.
- Fernald, M.L. 1950. Gray's Manual of Botany; eighth edition, illustrated. D. Van Nostrand Company. lxiv + 1632 pp.
- Fisher, T.R. 1988. The Dicotyledoneae of Ohio. Part 3. Asteraceae. Ohio State University Press, Columbus. 280pp.
- Flora of North America Editorial Committee. 2006. Flora of North America, North of Mexico. Volume 19: Magnoliophyta: Asteridae (in part): Asteraceae, part 1. Oxford University Press, New York. 579pp.
- 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.
- 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.