Carex oronensis

Illustrator: Susan A. Reznicek

Copyright: Flora of North America Association

Plants loosely cespitose. Culms 30–100 cm. Leaves: sheaths papillose, summits U-shaped; distal ligules 2.1–4.6 mm; blades 3–4 per fertile culm, 18–23 cm × 2–4 mm. Inflorescences stiffly erect, open, coppery brown, 1.5–3.4 cm × 6–15 mm; proximal internode (1–)3–6(–9) mm; 2d internode 1–4 mm; proximal bracts usually scalelike, occasionally bristlelike. Spikes (3–)5–6(–10), distant, individually distinct, rhomboid-ovoid, 5–10 × 3–7 mm, base and apex tapered. Pistillate scales mid to dark brown, usually with pale midstripe, glossy, lanceolate, (3–)3.5–3.7(–4) mm, subequal to perigynia in length and width, margin white-hyaline, to 0.15 mm wide, apex acute. Perigynia ascending, light green to straw colored, pearlescent, often with adaxial reddish brown blotch, conspicuously 7–15-veined abaxially, usually inconspicuously or conspicuously (6–) 9–12-veined adaxially, lanceolate, plano-convex, 2.9–4.3 × 0.9–1.4 mm, 0.6 mm thick, margin flat, including wing 0.07–0.4 mm wide, unwinged below median; beak brown, white-hyaline at tip, flat, ciliate-serrulate, abaxial suture conspicuous, often with narrow white-hyaline margin, distance from beak tip to achene 1.5–2.4 mm. Achenes ovate, 1.3–1.6 × 0.7-1.4 mm, 0.3–0.5 mm thick. 2n = 74.

Phenology: Fruiting summer (late Jun–mid Jul).
Habitat: Hay fields, forest edges, open woods
Elevation: 30–400 m

Distribution

• Generated Map
• Legacy Map

Maine.

Discussion

Of conservation concern.

Carex oronensis is in the Center for Plant Conservation’s National Collection of Endangered Plants.

Selected References

Dibble, A. C. and C. S. Campbell. 2001. Conservation status of Carex oronensis (Cyperaceae), a Maine endemic. Rhodora 103: 351–379.

Lower Taxa

None.