Small tree of fertile polyploid origin from the hybrid purpus birch (B. Xpurpursii), a cross between bog birch (B. pumila) and yellow birch (B. alleghaniensis), all characters intermediate between the parent species.
Status and Rank
- State Status: SC
- State Rank: S1
- Global Rank: G1Q
|County Name||Number of Occurrences||Year Last Observed|
Updated 7/21/2017. 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.
Only one known remaining specimen of this fertile polyploid exists in the wild. It occurs in a low swampy area adjacent to a lake in southern 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.
Paper birch, dogwood, trembling aspen, bog birch, and yellow birch.
Known globally from a single site in Washtenaw County. One of two documented individuals remains extant; further survey may turn up more individuals elsewhere in southeastern Michigan.
General Survey Guidelines
Random meander search covers areas that appear likely to have rare taxa, based on habitat and the judgment of the investigator.
- Meander search
Survey Period: From first week of May to fourth week of September
Survey Comments: Known from only one site globally
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- Flora of North America Editorial Committee. 1997. Flora of North America, North of Mexico. Volume 3: Magnoliophyta: Magnoliidae and Hamamelidae. Oxford University Press, New York. 590pp.
- Voss, E. G. 1985. Michigan Flora. Part II. Dicots (Saururaceae-Cornaceae). Bulletin of the Cranbrook Institute of Science and University of Michigan Herbarium. 724pp.