83. Carex emoryi Dewey

Pl. 53 i–l; Map 199

Plants with short- and long-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, 3–5(–8) mm wide, green. Leaf sheaths with the tip truncate to convex, the ligule mostly wider than long and U- or V-shaped, the ventral side white to yellowish tinged, usually lacking dots, the dorsal side green or reddish tinged, smooth, the lowermost sheaths reddish brown, not becoming dissected into fibers at maturity. Spikes 4–8 per stem, the lowermost bract shorter than to about as long as the inflorescence. Staminate spikes mostly 2(1–3), 15–55 mm long, the terminal spike short- to long-stalked, the lateral, staminate spikes (if present) sessile or nearly so. Staminate scales 2.5–6.0 mm long, oblong-obovate, rounded to bluntly pointed at the tip, awnless, reddish brown to purplish black with lighter midrib and white margins. Pistillate spikes 3–5, erect or ascending, 20–100 mm long, 3–5 mm wide, the uppermost sometimes staminate toward the tip. Pistillate scales 1.5–3.7 mm long, ovate or elliptic, bluntly pointed to long-tapered at the tip, reddish brown to purplish black with green midrib and usually white margins. Perigynia 1.7–3.2 mm long, elliptic to slightly ovate or obovate in outline, flattened and biconvex in cross-section, not inflated, with a short beak 0.1–0.3 mm long, truncate to minutely notched at the tip, with 3–7 fine (sometimes faint) nerves on each surface, green or straw-colored, lacking reddish brown dots. Styles withering during fruit development and jointed to the main body of the fruit. Fruits 1–2 mm long, oblong-elliptic to ovate in outline, minutely beaked at the tip, brown. 2n=72. May–July.

Scattered nearly throughout Missouri, but apparently absent from the Mississippi Lowlands Division (northeastern U.S. and adjacent Canada west to North Dakota, Colorado, and Texas; northeastern Mexico). Bottomland prairies, margins of streams and spring branches, and moist areas at the base of dolomite bluffs; sometimes emergent aquatics.

Carex emoryi and C. haydenii are easily misdetermined in spite of the differences in perigynium color and nervation. Other features separating these species include the absence of long-creeping rhizomes and lighter brown perigynia in C. haydenii. In C. haydenii, the perigynia are often somewhat shorter than the pistillate scales that subtend them, whereas in C. emoryi the perigynia are longer than the subtending scales. Unique features of C. emoryi include its convex ventral sheath tips and the shape of the pistillate spikes, which tend to taper in outline toward the base.