Carex retroflexa Muhl. ex Willd.

Plants without conspicuous rhizomes. Culms 10–75 cm, 1.3–1.8 mm wide basally, 0.5–0.8 mm wide distally. Leaves: sheaths tight, green, fronts hyaline; ligules less than 2 mm, wider than long; widest leaf blades 1.4–3 mm wide. Inflorescences with 3–9 spikes, 1–4 cm × 5–9 mm; proximal internodes 1–3 times as long as proximal spikes; proximal bracts to 6 cm; spikes with 3–10 spreading perigynia. Pistillate scales hyaline with green midvein, ovate, 2–3 × 1.4–1.6 mm, 3/4 length to equaling perigynia, apex acute to acuminate. Anthers 1.5–2.3 mm. Perigynia green to pale yellow, faces weakly veined, 2.5–3.2 × 1.2–1.8 mm, base of body spongy, thickened and longitudinally striate adaxially, spongy region 0.8–1.5 mm, margins entire, serrulate distally; beak 0.7–1 mm, apical teeth 0.1–0.3 mm. Stigmas straight or slightly twisted, 0.05 mm wide. Achenes ovate-circular, 1.3–1.6 × 1.3–1.5 mm. 2n = 40.