United States, Minnesota, Cook, Boundary Waters Canoe Area Wilderness, Rugged bedrock terrain northwest of Brule Lake, 24 miles northwest of Grand Marais. T63N R3W NE1/4 of SW1/4 Sec. 5
Locally common in broad mud flats in the western end of the narrow, bedrock-entrenched basin that encompasses Cuckoo Lake. Forming rather dense patches in the subtly higher and drier zone bordering the upland. Deep moist muck (and moist organic silt amongst small boulders on the upland margin). Full sun.
Associates include Rhynchospora alba, Dulichium arundinaceum, Eleocharis palustris, Juncus brevicaudatus, Agrostis scabra, Carex cryptolepis, C. michauxiana, C. utriculata, Glyceria grandis, Muhlenbergia uniflora, Drosera intermedia.