Rich deciduous forests; rather local. A very distinctive species with large trigonous perigynia.

A collection purported to be from Bay View, Emmet Co., far north of the known range of this plant, is not mapped. The collection is in quite young fruit – but the date was noted as "July-August," impossible for a plant in this stage. That, and the vague data, suggest a label error.

This is somewhat like the more frequent, and much more widespread, Carex plantaginea, but the leaves, besides being somewhat narrower on average, are smooth, not "puckered."