Carex pachystachya

Copyright: Flora of North America Association

Plants densely cespitose. Culms 15–120 cm. Leaves: sheath white hyaline or green-veined, summits usually U-shaped, often prolonged to 4 mm beyond collar; distal ligules 1–2.5 (–4) mm; blades 3–4 (–5) per fertile culm, 10–30 cm × 1.2–4.2 (–6.5) mm. Inflorescences dense or open, gold to dark-brown, 0.9–2.8 cm × 6.7–16.3 mm; proximal internode 0.7–4.5 (–9) mm; 2d internode 0.7–4 mm; proximal bracts usually scalelike, sometimes bristlelike, shorter than inflorescences. Spikes 3–9 (–13), distinct or densely aggregated and individually indistinct, ovoid to broadly ovoid, 4.4–10 × 3.2–8.7 mm, appearing coarse-textured, base acute to rounded, apex rounded. Pistillate scales dark gold or redbrown to dark-brown, usually with pale or green midstripe, ovate, 2.2–3.7 (–4.2) mm, less than or equaling perigynia in length and width, margin white, 0–0.15 mm wide, apex obtuse to long-acute. Perigynia ascending to spreading, golden brown or coppery to blackish, conspicuously (0–) 2–9-veined abaxially, conspicuously 0–4 (–7) -veined adaxially, veins reaching top of achene, ovate to elliptic-ovate, planoconvex, 2.8–4.7 (–5.1) × 1.1–2.3 mm, 0.5–0.7 mm thick, margin flat, including wing 0.2–0.4 mm wide, sometimes filled with pithlike tissue near base, ciliate-serrulate at least on distal body, occasionally with white margin, with metallic sheen; beak redbrown to black at tip, sometimes white-hyaline, cylindric, unwinged, ± entire for 0.4–0.7 mm, suture usually inconspicuous, distance from beak tip to achene 1.5–2.2 (–2.8) mm. Achenes elliptic to broadly ovate, 1.2–1.9 × 0.7–1.4 mm, 0.4–0.6 mm thick. 2n = 74.

Phenology: Fruiting summer.
Habitat: Moist to wet, open meadows, strands along lakeshores, forest edges
Elevation: 0–3500 m

Alta., B.C., Sask., Yukon, Alaska, Calif., Colo., Idaho, Mont., Nev., Oreg., Utah, Wash., Wyo., Asia (Siberia)

Discussion

Selected References

None.

Lower Taxa