430b. Carex tonsa (Fernald) E. P. Bicknell var. rugosperma (Mackenzie) Crins, Novon. 6: 118. 1996.
Carex à fruits rugueux
Carex rugosperma Mackenzie, Bull. Torrey Bot. Club 42: 621. 1915
Leaf blades bright green, much longer than culms, herbaceous, scabrous to papillose adaxially. Perigynia pubescent on beak and body.
Fruiting mid Apr–late Jun. Open, dry, acidic, sandy and rocky meadows, roadsides, dunes, ridges, heathlands, savannas, pine, oak, and poplar woodland edges; 50–1000 m; Man., N.S., Ont., Que., Sask.; Conn., Ga., Ill., Ind., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., S.C., Vt., W.Va., Wis.
Carex tonsa var. rugosperma has long been known as C. rugosperma but C. tonsa has priority. The two varieties of C. tonsa may occur together; intermediates are found occasionally. Plants with virtually glabrous perigynia may have long, scabrous leaves. Plants with a pubescent perigynia apparently never have coriaceous, short, and nearly smooth leaves.