84. Carex haydenii Dewey
Pl. 53 m–p; Map 200
Plants mostly with short-creeping rhizomes,
forming dense clumps. Flowering stems 40–120 cm long, mostly longer than the
leaves, erect to ascending, sharply trigonous and roughened on the angles,
reddish purple tinged at the base. Lowermost leaves reduced to nearly bladeless
sheaths. Leaf blades 5–60 cm long, 2–5 mm wide, green. Leaf sheaths with the
tip concave, the ligule as long as wide or longer than wide and V-shaped, the
ventral side white to yellowish tinged, usually with yellowish brown or reddish
purple dots, the dorsal side mostly green, smooth, the lowermost sheaths dark
reddish brown, not becoming dissected into fibers at maturity. Spikes 3–6 per
stem, the lowermost bract shorter than to about as long as the inflorescence.
Staminate spike(s) 1–3, 10–50 mm long, the terminal spike short- to
long-stalked, the lateral, staminate spikes (if present) sessile or nearly so.
Staminate scales 3–4 mm long, oblong-obovate, bluntly pointed at the tip,
awnless, reddish brown to purplish black with lighter midrib and white margins.
Pistillate spikes 2 or 3, erect or ascending, 10–50 mm long, 4–5 mm wide, the
uppermost sometimes staminate toward the tip. Pistillate scales 2.0–3.7 mm
long, ovate, pointed to long-tapered at the tip, reddish brown to purplish
black with green midrib and usually white margins. Perigynia 1.5–2.6 mm long,
elliptic to obovate in outline, flattened and biconvex in cross-section,
somewhat inflated at maturity, with a short beak 0.1–0.2 mm long, minutely
notched at the tip, nerveless or with 1–3 faint nerves on each surface in
addition to the 2 marginal ribs, olive green or brown with reddish brown dots.
Styles withering during fruit development and jointed to the main body of the
fruit. Fruits 1.0–1.5 mm long, elliptic to ovate in outline, minutely beaked at
the tip, light brown, somewhat iridescent. 2n=54. May–July.
Scattered in northern Missouri locally
south to Benton County (northeastern U.S. west to North Dakota and Nebraska; Canada). Bottomland prairies, margins of streams.
For a discussion of the separation of C.
haydenii from C. emoryi, see the treatment of that species.