Carex muehlenbergii var. enervis
Ill. Carex, 3: 124, plate 400. 1862.
Pistillate scales 2–2.5 × 1.2–1.8 mm. perigynia veinless adaxially, 2.7–3.1 × 1.8–2.3 mm, beak 0.2–0.6(–1.0) mm.
Phenology: Fruiting late spring–early summer.
Habitat: Dry grasslands, open forests, commonly on sand
Elevation: 10–300 m
Distribution
Ont., Ala., Ark., Conn., Ga., Ill., Ind., Iowa, Kans., Ky., La., Md., Mass., Mich., Minn., Miss., Mo., Nebr., N.H., N.J., N.Y., N.C., Ohio, Okla., Pa., R.I., S.C., Tenn., Tex., Vt., Va., W.Va.
Discussion
The distribution and ecology of Carex muehlenbergii var. enervis are unclear due to confusion with var. muehlenbergii. Plants of var. muehlenbergii that have a veinless perigynium have often been misidentified as var. enervis, but those plants are otherwise identical to var. muehlenbergii. Carex muehlenbergii var. muehlenbergii usually occurs on basic to slightly acidic soils; var. enervis often occurs on more acidic soils. It is not clear, however, whether that correlation is consistent.
Selected References
None.