A New Species of Cyperus (Cyperaceae) from Costa Rica and Mexico

Abstract

Cyperus herndoniae is described, illustrated, and compared to its nearest relative, C. distans. It is known from collections from Guanacaste Province, Costa Rica, and Chiapas, Mexico. During the course of my work on Cyperus in Costa Rica and Panama, an undescribed species was noted from two collections made by R. L. Wilbur in Guanacaste Province. Later, a third collection made by D. E. Breedlove in Chiapas, Mexico, was detected. Cyperus herndoniae Tucker, sp. nov., fig. 1.-TYPE: Costa Rica, Guanacaste, local in ditch at the entrance of the Santa Rosa National Park, 21 Jul 198 1, Wilbur 31825 (holotype: DUKE; isotypes: CR, F, GH, MO). Rhizoma ascendens, ad 2 cm longa. Radii simplices. Spiculae linearilanceolatae, 8-16 mm longae, 1.5-2.1 mm latae. Squamae divaricatae, ellipticae, 3-3.2 mm longae, 1.5-1.9 mm latae. Achaenium trigonum, oblongum, 2-2.2 mm longum, 0.6-0.7 mm latum. Affinis Cypero distanti L.f. Culms single or 2-3 together, 30-75 cm tall, trigonous, smooth; basally indurate. Rhizomes up to 2 cm long, turning upward. Roots fibrous. Leaves 1-4, 20-40 cm long, 2-3 mm wide, margins scabrellate. Inflorescence bracts 3-6, 2-25 cm long, 1-6 mm wide, borne horizontally, margins scabrellate. Rays (4-)6-8, up to 5 cm long, unbranched. Spikes ovoid to hemispherical, (5-)15-35 mm long, 17-45 mm wide; rachis 3-12 mm long. Spikelets (10-)25-50 per spike, linear-lanceolate, compressed, 816 mm long, 1.5-2.1 mm wide; rachilla slightly flexuous, its wings hyaline, 0.3-0.4 mm wide. Scales 4-12 per spikelet, elliptic, 3-3.2 mm long, 1.3-1.9 mm wide, obtuse, mucronulate, borne divaricately on the rachilla, laterally 2-3-nerved, brown to stramineous, the margins hyaline, the keel 3-nerved, greenish. Stamens 3; filaments ribbonlike, 3.5-4 mm long; anthers oblong, 0.9-1.1 mm long. Styles 0.4-0.7 mm long; stigmatic branches 3, 2.5-3 mm long. Achenes trigonous, oblong, 2-2.2 mm long, 0.6-0.7 mm wide, apiculate, slightly stipitate, angles rounded, faces flat to slightly convex, finely papillose, brown. Distribution. Roadsides, wet marshy depressions, and low flats from sea level to 700 m. Flowering and fruiting specimens have been collected in Jul, Aug, and Sep. Specimens examined. Costa Rica. Guanacaste: just outside Santa Rosa National Park, Wilbur 30970 (DUKE); 14 km S of La Cruz, Wilbur 30928B (DUKE); about 18 km N of