4b. var. nigromarginata
Pl. 30 a–d; Map 121
Plants with short-creeping rhizomes, forming
dense tufts. Pistillate spikes with the scales usually strongly tinged with
dark reddish purple, the margins narrow and white. 2n=34, 36. March–May.
Scattered in southern Missouri, in the
Ozark, Ozark Border, and Mississippi Lowlands (Crowley’s Ridge) Divisions
(eastern U.S. west to Wisconsin and Texas). Mesic and dry upland forests, often
on rocky slopes, on igneous, sandstone, cherty dolomite, and coarse-sandy
substrates.