96 CYPERACEAE (SEDGE FAMILY) 



pointed : pistillate spikes 5-8 cm. long, 8 mm. or more broad, upright, scattered, 

 loosely flowered at the base: perigynium very strongly nerved, smooth, ovate- 

 lanceolate, terminated by very conspicuous, divaricate, smooth, and slender 

 teeth, usually longer than the rough-awned scale. C. trichocarpa aristata. 

 Colorado and northward, thence across the continent. 



9. Sterile and fertile spikes one to several or many: fertile spikes mostly large 

 and compactly flowered: perigynium much inflated (cross section nearly twice 

 or much more than twice the width of the mature achenium), membranaceous, 

 smooth, conspicuously nerved (or nearly nerveless in No. 21), tapering into 

 a toothed beak as long as the body or longer. PHYSOCARPAE Drejer. Mostly 

 large and stout species. No. 21 is the least developed of the section, and 

 in some forms it appears to ally itself with other and very dissimilar sec- 

 tions. 



* Staminate spikes commonly more than one: pistillate spikes usually long and 

 densely cylindrical (short in No. 21 and occasionally in No. 24) : perigynium 

 smooth and shining, long-beaked, at maturity yellow or straw-colored, or oc- 

 casionally partly reddish-purple. VESICARIAE Tuckm. 



H Staminate spike one: pistillate spikes comose, cylindrical and drooping or 

 spreading: bracts sheathless or nearly so: beaks long. 



20. Carex hystricina Muhl. Willd. Sp. PL 4: 282. 1805. Plant rather slen- 

 der, pale, 3-5 dm. high: spikes 2-4, narrow, 2-5 cm. long, nodding or the upper 

 one nearly erect or spreading, decidedly comose in appearance: perigynium 

 15-nerved, not prominently inflated, prolonged into a very slender and setace- 

 ously toothed beak, the lobes of which are spreading: scales awn-like, shorter 

 than the perigynium. Wet places; New Mexico and northeastward to Ne- 

 braska and Wyoming. 



H- H- Staminate spike one, rarely two: pistillate spikes short, erect, more or 

 less purplish: beaks short: stigmas usually two. 



21. Carex saxatilis L. Sp. PL 976. 1753. Stoloniferous: culm 1-3 dm. 

 high, sharply angled, about the length of, or a little longer than, the narrow 

 and sharp-pointed leaves: pistillate spikes 1-3, the upper sessile or nearly so, 

 the lower mostly more or less peduncled, all dark purple or at maturity be- 

 coming brown: bracts narrow, long-pointed, shorter or a very little longer than 

 the culm: perigynium ovate-oblong or elliptic, nerveless or very inconspicu- 

 ously nerved at the apex, rather abruptly contracted into a very short nearly 

 entire beak, mostly longer than the more or less obtuse membranaceous scale. 

 C. pulla Gooden. C. vesicaria alpigena Fries. Rocky Mountains, from Colo- 

 rado to British America. 



21a. Carex saxatilis Grahamii Hook. & Arn. Brit. Fl. 8th Ed. 510. Stouter, 

 3-5 dm. high: perigynium lighter colored, often nearly straw-colored, promi- 

 nently few-nerved, the beak longer and more conspicuously toothed. High 

 mountains of Colorado, Utah and northward. 



H * Staminate spikes two or more: pistillate spikes normally long, spread- 

 ing or drooping: stigmas three. 



++ Perigynium conspicuously turgid, ascending at maturity. 



22. Carex Engelmannii Bailey, Proc. Am. Acad. 22: 132. 1877. Culma 

 slender but erect, 10-15 cm. high, about the length of the numerous very 

 slender bristle-like leaves: spike small, nearly globular, 4-6 mm. broad, the 

 staminate flowers inconspicuous: perigynium lanceolate, about 4 mm. long, 

 very delicate in texture, flat, somewhat shining, nerveless, the long apex 

 empty, the beak entire or nearly so, about the length of the thin brown acute 

 scale. Alpine slopes, Colorado. 



23. Carex monile Tuckm. Enum. Meth. 20. 1843. Culms usually more 

 slender and leaves a little narrower: spikes more slender: perigynium sub- 

 globose, much inflated towards the base, one half or more as broad as long, 



