Leaves usually bright green; widest blade 5.3-8.3 mm wide. Longest staminate spike 6-20(-23) mm.
Fruiting spring-early summer. Low, wet, deciduous or mixed deciduous-evergreen forests, mesic slopes to along edges of springs, seeps, and streams, usually clay soils; 0-1000 m; Ont.; Ala., Ark., Ill., Ind., Iowa, Ky., Mich., Mo., N.C., Ohio, Tenn., Va., W.Va., Wis.
Carex laxiculmis var. copulata has been treated as a variety of C. digitalis or C. laxiculmis, as a distinct species, and as a hybrid between C. digitalis and C. laxiculmis. Regular pairing during metaphase-I indicates that C. laxiculmis var. copulata is not a by-product of hybridization (R. F. C. Naczi 1999). In lateral spikes, a proximal sterile scale or scale subtending a staminate flower clearly places the affinity of this variety with C. laxiculmis rather than C. digitalis (C. T. Bryson 1980).
From Flora of Indiana (1940) by Charles C. Deam
Frequent in eastern Indiana in dry woods, principally white oak and beech; rare in the western counties. The variety is said to be a calciphile while the species prefers neutral or only slightly calcareous soils.