Plants and Animals
Potamogeton hillii Hill's pondweed
Aquatic plant of cool northern Michigan ponds; stem slender and branched; leaves alternate, submerged, and narrow (1-2 mm), with three parallel veins.
Status and Rank
State Status: T - Threatened (legally protected)
Global Rank: G3 - Vulnerable
State Rank: S2 - Imperiled
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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.
Hill's pondweed is found in cold, alkaline streams on sandy, mucky, and marly substrates. It usually occurs in water up to one meter in depth.
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.
Yellow water-lily, pondweeds, bulrush, white water-lily, and stonewort.
Maintain good water quality, cool water temperatures, and a relatively natural habitat. It sometimes persists in the vicinity of developments (homes, roads) suggesting that it can survive certain types or degrees of disturbance.
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement of the investigator.
Survey Period: From first week of July to fourth week of August
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- 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.
- Voss, E. G. 1972. Michigan Flora. Part I. Gymnosperms and Monocots. Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 488pp.