Descripcion

Description: Plant caespitose, rhizomes with short internodes, rarely some internodes slightly elongate. Fertile culms (10)15–50(60) cm, slightly shorter than or equalling the leaves, rarely slightly exceeding them, sharply trigonous, the faces sulcate, the angles smooth for most of its length, antrorsely scabridulous towards the apex, (0.2)0.5–1.0(1.1) mm wide at the middle of its length; basal sheaths brown to dark brown, early decomposing into fibres. Leaf blades 1.2–2.0(2.5) mm wide, flat, glabrous, margins and nerves antrorsely-scabrid for most of their length; ligule truncate to rounded, protruding into the blade 0.5–1.5 mm, the free portion hyaline to reddish-brown. Inflorescence (0.5)0.8–1.5(2.5) cm long, 6–1(14) mm wide, congested, suborbicular to shortly ovate, rarely elliptical, the spikes aggregated or rarely the lowermost one slightly separated by an internode shorter than it, still overlapping with the spike(s) immediately above; proximal-most bract leaf-like to filiform (2.5)5.0– 11.0 cm × 0.5–1.0(1.8) mm, long exceeding the inflorescence, the immediately adjacent bract longfiliform, also surpassing the inflorescence. Spikes three to six, androgynous, with five to 12 spreading utricles, the distal ones the smallest, crowded and almost undistinguishable, the proximal ones larger and more conspicuous, compound spikes absent. Female glumes 2.3–3.0 × 1.4–1.5 mm, shorter than to equalling the utricles, ovate, acute or subulate, almost entirely whitish-hyaline or pale browntinged near the midnerve, with one to three nerves at the middle, the grooves between nerves greenish to stramineous; male glumes c. 2.0 × 0.5 mm, elliptic, subulate to mucronate, entirely whitish hyaline, with a narrow inconspicuous greenish or stramineous middle nerve. Utricles 2.5– 4.0 × (1.8)2.0–2.5 mm, plano-convex, the body broadly ovate to suborbicular, pale greenish to stramineous, the margins antrorsely-scabridulous for most of their lengths, especially towards apex, abruptly constricted into a 0.5–1.0 mm shallowly bidentate beak with parallel sides, the faces profusely verrucose to almost muricate, nerveless to faintly nerved distally, the base with a three- to six-nerved corky bulge that may reach the middle of the utricle body. Nutlets narrowly biconvex, suborbicular to broadly ovate, yellowish to brownish, 1.5–1.8 × 1.5–1.6 mm, closely enveloped by the utricle, the base constricted to form a substipitate base, the style base shortly conical. Diagnosis: This new species is similar to C. bonariensis, from which it differs by the broadly ovate to suborbicular utricle body, abruptly contracted into a parallel-sided beak.