Coefficient of Conservatism:
Coefficient of Wetness:
A. A. Reznicek
Interdunal calcareous flats, fens, rock pools (Isle Royale), marly shores.
This species is a tetraploid derived from hybridization of D. linearis with D. rotundifolia and doubling of the chromosome number. The F1 hybrids, however, also occur in Michigan, and may be expected wherever the parents grow near each other. These hybrids are sterile, the ovules and seeds aborting and no ripe fruit developing. Like the parents (and D. intermedia) they are diploid (2n = 20). Otherwise, they may be morphologically indistinguishable from the fertile tetraploid, though often the sterile hybrid can be strongly suspected when solitary or very few scattered plants are seen with both parents, rather than in populations.