Lemna valdiviana
Pale duckweed

Key Characteristics

Floating aquatic duckweed of shallow lakes; plants with one root per leaf node; leaves ovate, tiny (1-2 mm) with one vein.

Status and Rank

  • State Status: X
  • State Rank: SX
  • Global Rank: G5


County NameNumber of OccurrencesYear Last Observed
Distribution map for Lemna valdiviana

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.


Known only from two collections in the 1940's from a millpond in Kalamazoo County.

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 collection data are known for the Michigan collections. It would likely occur with more common duckweeds such as the very similar Lemna minor and other aquatics like great duckweed (Spirodela) and water meal (Wolffia spp.).


The principal need for this species, which is currently classified as extirpated in Michigan, is conducting surveys in southwest Michigan to discover if there are any extant colonies. This tiny aquatic plant is very similar to common duckweed, and thus could be easily overlooked. If found, it would likely require protection of hydrology.

General Survey Guidelines

Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgement 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 Sep 25, 2018]


Survey References

Technical References

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