CYPERACEAE (SEDGE FAMILY) 97 



abruptly short-beaked, 10 or less-nerved: otherwise as in the last. Colorado 

 and Wyoming. 



23a. Carex monile colorata Bailey, Mem. Torr. Bot. Club 1: 39. 1889. 

 Smaller: spikes shorter than in the species, dark brown: perigynium very 

 much less turgid and shorter beaked: scales shorter and not so sharp. Colo- 

 rado, northward and westward. 



++ -M- Perigynium not conspicuously turgid, squarrose at maturity, and the 

 spikes comose in appearance. 



24. Carex utriculata Boott, Hook. Fl. Bor. Am. 2: 221. 1840. Somewhat 

 stoloniferous: culm very stout, 3-10 dm', high, acutely angled above, very 

 thick and spongy at the base: leaves broad, 4-12 mm., carinate at the base, 

 much exceeding the culm, conspicuously nodulose-reticulated: pistillate 

 spikes 2-6, more or less remote, the upper sessile, the lower often on weak 

 peduncles 3-5 cm. long, long-cylindrical or terete, 3-15 cm. long, thick and 

 compactly flowered (sometimes loosely flowered at the base), often stami- 

 nate at the top: perigynium ellipsoid or globose-ovoid, usually gradually 

 tapering into a short beak, broader and commonly longer than the very acute 

 or rough-awned scale. Var. minor Sartwell, is a form smaller in all its 

 parts, with spikes 2-3 cm. long. Common in swamps from Colorado and 

 Utah northward. 



10. Staminate spikes one or more, long: pistillate spikes one to several, brown, 

 purple or greenish, commonly approximate, sessile or peduncled, oblong or 

 linear, mostly elongated: perigynium not inflated, biconvex, minutely beaked 

 or beakleUt, smooth: stigmas 2. MICRORHYNCHAE Drejer. Paludose and 

 alpine species of upright habit, often growing in tufts or tussocks. Our 

 species fall under the group Acutae Fries. 



* Perigynium strongly nerved. 



25. Carex nebraskensis Dewey, Am. Journ. Sci. II. 18: 102. 1854. Gla- 

 brous: culms stout, sharp-angled, 3-6 dm. tall: leaves pale green, 3-5 mm. wide, 

 rough-margined, their sheaths more or less nodulose: lower bract sometimes 

 equaling the culm, the upper much shorter and narrower: staminate spikes 

 commonly 2, stalked: pistillate spikes 2-4, dense, oblong-cylindric, erect, 2-3 

 cm. long, about 6 mm. in diameter, sessile or the lower short-stalked: perigynia 

 elliptic or obovate, prominently several-ribbed, short-beaked, the beak 2- 

 topthed: scales ovate or lanceolate, acute or mucronate, brown with green 

 mid vein or green all over, the upper shorter than the perigynia: stigmas 2. 

 Nebraska to Oregon and New Mexico. 



* * Perigynium slightly nerved or nerveless. 

 H Robust species: bracts leaf -like, usually exceeding the culm. 



26. Carex aquatilis Wahl. Kongl. Acad. Handl. 24: 165. 1803. Stolonifer- 

 ous: culm obtusely angled, 5-10 dm. high, smooth, leafy: leaves flat, pale, 

 scarcely longer than the culm: pistillate spikes 2^4, erect, thick and compactly 

 flowered throughout or more commonly inclining to club-shaped with a 

 gradually attenuate base, the upper sessile, the lower more or less peduncled 

 and often long exserted : perigynium broadly elliptic or obovate, rarely circular, 

 nerveless, tipped with a minute and entire point, green or light-colored, wider 

 and either longer or shorter than the green or purple-margined acutish scale. 

 A large species, in wet places; generally distributed northward. 



- Low, or tall and slender species: bracts mostly short and narrow, often 



setaceous. 



++ Culms slender and tall: leaves with more or less revolute margins when dry. 



27. Carex physocarpa Presl. Relig. Haenk. 1: 205. 1830. Culms erect, 2-3 

 dm. high: peduncles relatively long, rough, 3-10 cm.: spikes oblong, brown, 



ROCKY MT. BOT. 7 



