Occasional to frequent in poor conifer swamp and black spruce bog. Patchy canopy dominated by Picea mariana, with occasional Larix laricina. Partial shade. Continuous Sphagnum carpets. Deep, wet, moderately buoyant peat. Densely cespitose. Mostly on raised areas around tree bases and other hummocks. Many hundreds of clumps here, larger ones with 12-25 fertile culms.