38. Carex debilis Michx. var. debilis

Pl. 40 i–l; Map 154

Plants with the rhizomes absent or very short-creeping, forming dense tufts or clumps, the sheaths of previous season’s basal leaves sometimes persisting and becoming more or less dissected into hairlike fibers. Vegetative stems well developed, with several leaves. Flowering stems 25–110 cm long, longer than the leaves, sharply trigonous, glabrous and mostly smooth, strongly purplish tinged at the base. Lowermost leaves often reduced to nearly bladeless sheaths. Leaf blades 1–45 cm long, 2–4 mm wide, light green, flat, glabrous. Leaf sheaths concave at the tip, glabrous to minutely hairy only on the dorsal side, the ligule longer than wide and V-shaped, the ventral side thin, yellow-brown tinged and sometimes with inconspicuous reddish purple spots or streaks, the lowermost sheath bases strongly purplish tinged. Terminal spike staminate, 15–35 mm long, linear, the staminate scales 4–7 mm long, oblanceolate to obovate, rounded to pointed at the tip, white with a green midrib. Lateral spikes 2–4, pistillate, 25–60 mm long, 3–4 mm wide, short- to long-stalked, mostly nodding or drooping, the scales 3–6 mm long, ovate to oblong-ovate, rounded at the tip, white or pale green, with a green midrib, the margins sometimes light brownish tinged. Perigynia 6–10 mm long, 1.5–2.0 mm wide, narrowly lanceolate in outline, broadest below the middle, circular to slightly trigonous in cross-section, tapered to a slender beak with 2 white, minute, papery teeth at the tip, tapered to a stalklike base, the sides strongly 2-ribbed, otherwise with several faint nerves, light green. Fruits 1.9–2.4 mm long, yellowish brown, with the sides flat to concave near the base and the angles somewhat thickened, tapered to a prominent, stalklike base, the tip tapered to a short, straight beak. 2n=60. May–July.

Uncommon in southeastern Missouri (eastern U.S. west to Texas, mostly on the Atlantic and Gulf Coastal Plains). Bottomland forests and acid seeps.

Steyermark (1963) included var. rudgei L.H. Bailey in his treatment of this species with the cryptic statement, “Recorded from Missouri,” and without citation of specimens, suggesting that he was unable to verify its existence in the state. The origin of this report, which also was accepted by Gleason and Cronquist (1991), apparently was Mackenzie’s (1931–1935) treatment of the species for the North American Flora series, in which he included Missouri in a list of states from which he examined material. This variety, which differs from var. debilis in its shorter perigynia that are broadest near the middle and less distinctly beaked, is restricted to the northeastern United States and adjacent Canada, south to Virginia and west to Indiana. No specimens from Missouri were located during the present study, nor have any been seen by Dr. Marcia Waterway (McGill University, personal communication), who is preparing a monograph of this group. It seems unlikely that it will be found growing in Missouri.