Ranunculus ambigens

Key Characteristics

Stout amphibious perennial of streams; stem often lax, rooting at leaf nodes; leaves unlobed, lanceolate, 7 cm long or more (longer than petioles) with tiny well-spaced teeth on the margin; flowers yellow with 5 petals.

Status and Rank

  • State Status: T
  • State Rank: SX
  • Global Rank: G4


County NameNumber of OccurrencesYear Last Observed
St. Clair11904
Distribution map for Ranunculus ambigens

Updated 5/15/2018. 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.


Spearwort is known only from ditches and streams in St Clair County and from a springy hillside in Ottawa County. Elsewhere, this species is generally known from wet clay soils in northern and deciduous forests.

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

No data are available concerning associates in Michigan.


The primary need for this species is status survey, as it was last observed in 1940. If found, it would likely benefit from protection of stream hydrology.

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

Page Citation

Michigan Natural Features Inventory. 2007. Rare Species Explorer (Web Application). Available online at http://mnfi.anr.msu.edu/explorer [Accessed Aug 16, 2018]

More Information

See MNFI Species Abstract


Survey References

Technical References

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