Carex purpurifera Mack.

Carex purpurifera Mackenzie, sp. nov
Cespitose, the rootstocks very short-prolonged, the clumps medium-sized, the culms largely lateral and aphyllopodic, 2-4 dm. high, not strict, erect, ascending or decumbent, exceeding the leaves, slender, triangular, not at all flattened in drying, the angles irregularly and sharply papillose, very strongly bright-purple-tinged at base; sterile shoots elongate, forming conspicuous culms; leaf-blades of the sterile shoots erect, flat, thin, not semi-evergreen, green or in age yellowish-green, 3-8 mm. wide, the longer 1.5-2.5 dm. long, roughened on the margins and towards the apex on the veins, sharp-pointed, conspicuously whitishstriolate beneath, the midvein prominent on the lower surface and the two mid-lateral veins on the upper; leaves with well-developed blades 3 to several to a fertile culm, the blades similar but smaller, the sheaths long, only slightly enlarged upwards, not strongly serrulate, very thin and whitish-hyaline ventrally, conspicuously prolonged at mouth, the ligule conspicuous, longer than wide; staminate spike long-peduncled, linear, 2-3 cm. long, 3.5 mm. wide, strongly overtopping the pistillate spikes and their bracts, the scales oblong-obovate, obtuse, or slightly mucronate, dull-purplish-brown with several-nerved lighter center and narrow hyaline margins, the peduncle minutely serrulate; pistillate spikes 2 or 3, all widely separate, the upper erect and slightly or not at all exsert-peduncled, the lower strongly exsert-peduncled, the peduncles very slender, weak, terete, slightly roughened, the spikes 2.5-5 cm. long, 3-4 mm. wide, very loosely 4-15-flowered, the perigynia alternately arranged in few rows, strongly separate and not overlapping, erect, the uppermost scales often empty, the rachis granular, sharp-edged, the joints enlarged upwards; bracts strongly sheathing, not purple-tinged nor strongly serrulatemargined, the blades rather short, much exceeded by the culm; scales obovate or oblongobovate, very thin and membranaceous, more or less purplish-tinged, often refuse, usually whitish-hyaline with 3-nerved green center excurrent as a conspicuous rough awn, as wide below as the perigynia but usually shorter; perigynia oblong-obovoid, not at all inflated, obtusely triangular, 3.75-4.25 mm. long, nearly 2 mm. wide, membranaceous, glabrous, many-nerved, dull-green, in age greenish, stramineous, strongly stipitate, contracted into a spongy base (the stipe 0.5-1 mm. long), tapering into the straight or slightly excurved beak 0.25 mm. long, the orifice oblique; achenes obovoid, closely filling the upper part of perigyniumbody, 2.5 mm. long, 1.5 mm. wide, triangular with concave sides and blunt angles, granular, dull-yellowish-brown, subsessile, short-apiculate, jointed with the very short style; stigmas three, slender, reddish-brown.
Rhizomata brevissima; culmi cespitosi 2-4 dm. alti triangulares, basi valde purpurascentes; culmi steriles elongati; vaginae bractearum vix serrulatae; spicae stamineae pedunculatae lineares 2-3 cm. longae, squamis oblongo-obovatis viridi-albis vel fuscotinctis; spicae femineae lineares 2.5-5 cm. longae laxissime 4-15-florae; perigynia alterna pauciseriata oblongoobovoidea obtuse triangularia valde stipitata circ. 4 mm. longa, rostro recto vel paullo excurvato.
Type collected in open woods on hillsides and tops of cliffs, one mile south of Morley station, Campbell County, Tennessee; the region is strongly calcareous. (John Bright, May 18, 1923, in the Britton Herbarium.)
Distribution: Known only from the type locality, and from Mount Guyot, Cosby, Cocke County, Tennessee.