210 CYPERACEAE 



Lower culm sheaths strongly yellowish-brown tinged, sharply keeled; culms stout, the leaf- 

 blades 6 to 12 mm. wide - 109. C. schottii. 



Lower culm sheaths purplish-tinged, not sharply keeled; culms more slender, the leaf -blades 

 narrower 110. C. senta. 



B. SOME OR ALL OF THE FLOWERING CULMS ARISING LATERALLY AND NOT ENVELOPED AT BASE 



BY PREVIOUS YEAR'S TUFT OF LEAVES. 

 Culms very densely cespitose, forming dense stools; lowest sheaths strongly filamentose; lowest 



bract little developed, usually much exceeded by inflorescence 111. C. nudata. 



Culm much less densely cespitose, forming beds, conspicuously stoloniferous; lowest bract well- 

 developed, from somewhat shorter than to exceeding inflorescence. 



Perigynia orbicular or nearly so 112. C. eurycarpa. 



Perigynia oblanceolate 113. C. oxycarpa. 



29. Cryptocarpae. 

 Perigynia dull, straw-colored or light brown, slightly granular; lower sheaths of sterile shoots 



not filamentose 114. C. lyngbyei. 



Perigynia shining, brown, smooth; lower sheaths of sterile shoots strongly filamentose 



115. C. obnupta. 

 30. Trachychlaenae. 



Eepresented by one species in our range 116. C. spissa. 



31. Hirtae. 

 Beak of perigynium obliquely cut, shallowly bidentate at maturity; foliage pubescent; stam- 



inate scales long-ciliate 117. C. yosemitana. 



Beak of perigynium deeply bidentate; staminate scales at most erose. 

 Foliage not pubescent; teeth of perigynium beak short. 



Lowest bract strongly sheathing; fertile culms phyllopodic with many leaves, the sheaths 



not breaking and becoming filamentose 118. C. oregonensis. 



Lowest bract not sheathing; fertile culms aphyllopodic with few leaves, the sheaths 



breaking and becoming filamentose 119. C. lanuginosa. 



Sheaths and under surface of leaf -blades hairy; teeth of perigynium beak conspicuous 



120. C. sheldanil 

 32. Extensae. 



Represented by one species in our range 121. C. viridula. 



33. Physocarpae. 

 Perigynia ascending; lower sheaths more or less strongly filamentose; culms sharply triangular. 



Perigynia 4 to 8 mm. long, abruptly contracted into beak 122. C. vesicaria. 



Perigynia 7 to 10 mm. long, tapering into beak 123. C. exsiccata. 



Perigynia spreading at maturity; lower sheaths not filamentose; culms bluntly triangular below 



spikes 124. C. rostrata. 



34. Pseudo-Cypereae. 

 Perigynia suborbicular in cross-section, more or less inflated; teeth of perigynium beak 0.5 to 



1 mm . long 125. C. hystricina. 



Perigynia obtusely triangular, scarcely inflated, closely enveloping achene; teeth of perigynium 

 beak 1.5 to 2 mm. long, recurved or spreading 126. C. comosa. 



Sect. 1. Inflatae Kiik. Cespitose, the rootstocks elongate. Leaf -blades filiform. Spike soli- 

 tary, ovoid, androgynous, densely flowered, bractless. Perigynia inflated, the walls very 

 thin, slightly nerved, sessile, the smooth beak hyaline-tipped, obliquely cut, in age bidentu- 

 late. Achenes triangular. Stigmas 3. 



1. C. engelmannii Bailey. Culms 5 to 20 cm. high ; spike 10 to 15 mm. long, 

 6 to 10 mm. wide, the lower % pistillate; scales acute to cuspidate, all except 

 lower shorter than perigynia ; perigynia 4.5 to 5 mm. long, 2.25 mm. wide. 



Alpine peaks or meadows, Sierra Nevada in Tulare Co. North to Washing- 

 ton, east to Colorado. 



Locs. Kaweah Peaks, Dudley 2215; Chagoopa Mdws., Dudley 2272. 



Eef. CAREX ENGELMANNII Bailey, Proc. Am. Aead. 22:132 (1886), type coll. by Engelmann, 

 probably near Colorado Sprs., Colo. 



2. C. breweri Boott. (Fig. 28.) Culms 1 to 2.5 dm. high; spike 1 to 2 cm. 

 long, 6 to 10 mm. wide, the upper third staminate ; scales ovate, short-acuminate, 

 narrower and shorter than perigynia ; perigynia 5 mm. long, 3.5 mm. wide. 



High alpine peaks of the Sierra Nevada from Mt. Whitney to Mt. Shasta. 

 North to Washington. 



Locs. Mt. Whitney, Jepson 1085 ; head of San Joaquin River, Brewer 2831 ; Mt. Dana, 

 Brewer 1863; Mt. Shasta, Jepson. 



Refs. CAREX BREWERI Boott, 111. Carex 4:142, pi. 455 (1867), type loc. Mt. Shasta, Brewer 

 1422; Mackenzie, Erythea 8:18, fig. 1 (1922) ; Kiik. in Engler, Pflzr. 4 20 :96, fig. 20H-K (1909). 



