136.
Carex
tribuloides
Wahlenberg, Kongl. Vetensk. Acad. Nya Handl. 24: 145. 1803.
Carex tribuloïde
Plants densely cespitose. Culms 50—110 cm; vegetative culms with numerous leaves spaced evenly along distal 1/2. Leaves: sheaths adaxially green-veined nearly to collar, with ± triangular white-hyaline area to 3—8 mm proximal to collar, somewhat loose, expanded near summits, ± wing-angled, adaxially firm, summits U-shaped, somewhat thickened, slightly prolonged beyond collar; distal ligules 4—8(—12) mm; blades 4—10 per fertile culm, 15—40 cm × (2—)3—7 mm. Inflorescences erect, dense distally, brown, 2—5(—8) cm × 10—20 mm; proximal internode 2—20 mm; 2d internode 2—13 mm; proximal bracts bristlelike, 1(—8) cm. Spikes 6—15, overlapping or distinct, ovoid-oblong to globose, 6—12(—16) × 4—8 mm, base rounded to tapered, apex rounded. Pistillate scales white-hyaline or pale silvery brown with green midstripe, lanceolate, (1.9—)2.5—3 mm, 1/2 length of and narrower than perigynia, apex acute to acuminate. Perigynia more than (30—)40 per spike, appressed-ascending to ascending, pale green to pale brown, 3—6-veined abaxially, conspicuously or, occasionally, faintly, 2—4-veined adaxially, often somewhat asymmetric, ovate-lanceolate to ovate-elliptic, plano-convex, 3—5.4 × 1.1—1.7 mm, 0.3—0.5 mm thick, margin flat, including wing 0.1—0.5 mm wide; beak tip flat, ciliate-serrulate, abaxial suture with golden to dark brown hyaline margin, distance from beak tip to achene 1.4—2 mm. Achenes oblong-ovate, 1—1.8 × 0.6—0.9 mm, 0.3—0.5 mm thick. 2n = 70.
Varieties 2 (2 in the flora): North America; Mexico (Veracruz).
See note under 146. Carex longii.
