Carex pigra, a New Species of Carex Section Griseae (Cyperaceae) from the Southeastern United States of America

Abstract

Carex pigra is described as new from Alabama, Florida, Georgia, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia. Loosely and few-flowered pistillate spikes, long staminate spike peduncles, perigynia usually 3.9-4.5 mm long, and achenes occupying most of the space within the perigynia are among the characters distinguishing C. pigra from what are probably its closest relatives, C. flaccosperma and C. glaucodea. Carex pigra occurs mostly in moist to wet deciduous forests. Carex sect. Griseae (L. H. Bailey) Kiikenthal is a group of sedges endemic to eastern North America that is most diverse in mesic deciduous forests of the southeastern United States. Numerous (usually 40 or more), longitudinal sclerenchyma traces (nerves of earlier authors, e.g., Fernald, 1950; Gleason & Cronquist, 1991) that are impressed in living and dried perigynia are apomorphies diagnosing the section. Additional characters shared by members of section Griseae, though not unique to them, include glabrous leaf and bract blades, longsheathing lower bracts, usually unisexual spikes with only the terminal one staminate, and glabrous perigynia with entire apices. This section (including sect. Oligocarpae (Carey) Mackenzie) contains twenty-one species, one of which I describe here as new. This new species is more widespread and frequent than any of the six other species recently described as new in section Griseae, which are narrow endemics or rare (Bryson et al., 1987; Kral et al., 1987; Bridges & Orzell, 1989; Naczi, 1989, 1993). Carex pigra Naczi, sp. nov. TYPE: U.S.A. Mississippi: Lowndes County, 1.8 mi. W of Mayhew, ca. 0.3 mi. E of Oktibbeha County border, ca. 0.5 mi. W of junction of routes 45 Alternate and Old 82, 15 May 1989, Naczi 2174A & Bryson (holotype, MICH; isotypes, KNK, NCU, NY, US, herb. Bryson). Figure 1. A Carex flaccosperma spicis femineis angustioribus, perigyniis brevioribus et ascendentioribus, perigyniis (1.7-)1.8-2.0plo longioribus quam corporibus acheniorum, stipitibus acheniorum brevioribus, rostris acheniorum flexis differt; a Carex glaucodea perigyniis paucioribus, laxioribus, longioribus, et (1.9-)2.1-2.6(-2.8)plo longioribus quam latioribus differt; a speciebus ambabus pedunculis spicarum terminalium longioribus differt. Perennial herb, densely caespitose. Rhizomes short, 0.2-6 mm long between shoots or branches of the rhizomes, with internodes 0.2-4.2 mm long, 1.2-2.8 mm thick, covered with cataphylls 2-5 mm long. Shoot bases usually surrounded by cataphylls but not by bases of old leaves, stramineous. Reproductive shoots 10-51 cm tall, erect to spreading, elongating slightly in fruit; culms 0.6-1.3 mm wide at mid-height, smooth throughout, obtusely trigonous. Cataphylls glabrous, stramineous to whitish, multicostate. Leaves of reproductive shoots 2-5, arising in basal 0.004-0.13 of culms, the longest 0.37-0.85 times as long as culms; blades 4.8-20 cm long, 3.8-12.3 mm wide, the widest 6.1-12.3 mm wide, glaucous, flat to barely plicate, margins smooth or antrorsely scaberulous, adaxial surface smooth or sparsely antrorsely scaberulous on main veins, abaxial surface smooth; leaf sheaths 1.7-4.7 cm long, loose, glabrous, glaucous with bases whitish or stramineous; adaxial face of sheaths with hyaline and glabrous band, hyaline band with apex slightly concave to slightly convex; ligules 3.8-6.8 mm long, lingulate with apex obtuse. Vegetative shoots 13-33 cm tall, 0.50-0.82 times as tall as culms; leaves 4-6, similar to those of culms except blades 6.3-27 cm long; pseudoculms 2.1-6.9 cm tall, 3.2-5.2 mm wide, 0.15-0.22 of vegetative shoot height. Infructescences 8.7-47 cm long, 0.71-0.93 of culm height, usually with the upper 2-3 spikes overlapping, rarely with all spikes separate; the uppermost lateral spikes 0.3-11.4 cm distant; the lower spikes separate, 4.0-18 cm distant; lowest bract with blade 6.2-18 cm long and 0.31-0.70 times as long as culm, sheath 0.9-4.7 cm long, adaxial face of sheath with glabrous and hyaline band occupying full length or a portion of sheath, hyaline band with apex slightly convex and elongated 0.2-2.2 mm above sheath apex, sheath glabrous abaxially, ligule (3.0-)5.2-10.2 mm long; NovoN 7: 67-71. 1997. This content downloaded from 157.55.39.156 on Tue, 13 Jun 2017 18:00:54 UTC All use subject to http://about.jstor.org/terms