Carex pachystachya

Illustrator: Susan A. Reznicek

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 red-brown 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, plano-convex, 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 red-brown 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

Distribution

• Generated Map
• Legacy Map

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

Discussion

Selected References

None.

Lower Taxa

None.