Callitriche hermaphroditica
Autumnal water-starwort
Image of Callitriche hermaphroditica

Photo by William S. Alverson 

Key Characteristics

Slender aquatic annual of the Upper Peninsula; leaves all submersed, linear, opposite, deep green in color; fruit ripening very late (September to November) with conspicuous wings.

Status and Rank

  • State Status: SC
  • State Rank: S2
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
Distribution map for Callitriche hermaphroditica

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.


Occurs in shallow water, up to 3-4 feet deep, often found stranded on sand flats or muddy stream edges, or in shallow portions of marshes.

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

Common water-starwort, yellow water crowfoot, water-parsnip, mermaid weed, three-way sedge, and chara.


Relatively little is known of the biology of this species, other than that it requires maintenance of wetland hydrology. Further inventory is desirable.

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 [Accessed Aug 18, 2018]


Survey References

Technical References

Facebook link