Novon 12: 510, fig. 1. 2002.
Plants densely cespitose; longer rhizomes internodes 0.2–6 mm, 1.2–2.2 mm thick. Culms purple-red to (3.2–)4.1–7.4 cm at base, 11–41 cm; vegetative shoots 26–42 cm, 0.72–1.3 as long as culms. Leaves: deep green or proximal ones whitish proximally, widest blades of culms (3.7–)4.3–5.5 mm wide. Inflorescences: 8.8–36 cm, 0.68–0.95 of culm height; internodes between proximal scales in proximalmost spike 2.4–3 mm; internodes between distal lateral spikes 1.4–13 cm, longest internode (per plant) between distal lateral spikes 3.1–13 cm; peduncle of terminal spike 1.4–9.8(–14.1) cm, longest peduncle per plant 1.8–9.8(–14.1) cm; proximal bract sheaths tight, hyaline band of adaxial face with apex truncate, concave, or slightly convex, elongate to 1.3 mm beyond apex; ligules 4–4.9(–9.6) mm; blades white between veins proximally; bract blade of distalmost lateral spike usually exceeding or occasionally exceeded by terminal spike; longest bract blade of distalmost lateral spike 4.9–12 cm. Spikes 2–5, widely separate or the distalmost 2 overlapping; lateral spikes pistillate, with (2–)4–7(–11) perigynia, longest per plant with 5–7(–11), 6–21 × 3.2–5.7 mm, ratio of longest lateral spike length (in mm) to perigynia number = 2–2.4; terminal spikes 12–49 × (1.3–)2.1–4 mm, longest per plant (21–)26–49 mm, usually much exceeding distalmost lateral spike. Pistillate scales 2.8–4.8 × 1.6–2.1 mm, body (2–)2.3–2.9 mm, midrib prolonged as awn 0.6–2.8 mm. Staminate scales 4.2–6.5 × 1.6–2.4 mm, apex obtuse or acute, awnless. Perigynia distichously imbricate, ascending, prominently 49–64-veined, narrowly obovate or narrowly elliptic, obtusely trigonous in cross section, (3.7–)4.2–4.9 × 1.6–1.9, 2.3–2.7(–2.9) times as long as wide, 1.6–1.8(–1.9) times as long as achene bodies, base tapered, apex gradually or abruptly tapered; beak absent or straight, 0–0.7(–0.9) mm, 0–17% of perigynium length. Achenes 3.1–3.3 × 1.5–1.8 mm, tightly enveloped by perigynia, base abruptly contracted, apex abruptly contracted; stipe straight, 0.3–0.6 mm; body 2.4–2.7 mm; beak straight, 0.2–0.3 mm.
Phenology: Fruiting spring.
Habitat: Dry-mesic to mesic deciduous forests, usually in humic, sandy loams
Elevation: 40–300 m
Of conservation concern.
Carex acidicola is very rare and local; collections come from only ten populations. It usually occurs in small populations and frequently occurs with C. superata.