206 



CYPERACEAE (SEDGE FAMILY) 



14. C. siliaea. 



18. C.BieknelUi. 



15. C. alata. 



16. O. suberecta. 



Spikes brownish-white, of closely appressed ob- 

 scurely beaked firm perigynia .... 

 Spikes ferruginous; the abrupt slender beaks of 

 the perigynia with loosely ascending or spread- 



ing tips . . . . • • (12) C. hormathodes, v. Bicht^ 

 V. Inflorescence stiflF*(or, 'if flexuous, with brown or 

 ferruginous spikes) W. 

 W. Perigynia 5.6-7." mm. long, very thin, scale-like, 



almost transparent; scales blunt 

 W. Perigynia less than 5.6 mm. long, firm and opaque 

 (when exceptionally longer in C. alata, with 

 aristate scales) X. 

 X. Scales long-acuminate or aristate ; perigynia 

 4-5.5 mm. long; achenes oblong. 

 Spikes green or finally dull brown ; scalesjance- 

 subulate ; perigynia obovate, 2.8-3.7 mm. 

 broad, abruptly narrowed at base 

 Spikes becoming dark brown or ferruginous ; 

 perigynia 2.3-2.S mm. broad. 

 Spikes closely approximate; scales ovate- 

 lanceolate; perigynia ovate, tapering 

 gradually to the beak .... 

 Spikes scattered in a flexuous inflorescence ; 

 scales lanceolate; perigynia orbicular, 



abruptly slender-beaked . . (12) C. hormathodes, v. Rxcht-. 

 X. Scales blunt or at most acutish. 



Spike- gray-green or finally dull brown, witn 



Strongly appressed-ascending very firm ,, , ^ 



perigynia 3.5-4 (very rarely 4.5) mm. long 9. C. albolutescens. 

 Spikes "straw-colored or ferruginous, with 

 spreading-ascending perigynia 4-5.5 mm. long. 

 Inflorescence ofo-lO mostly distinct spikes . IJ C festucacea 

 Inflorescence of 3-6 approximate spikes (17) C. fesiucacea, v. brevior- 

 B Tips of the perigvnia equaled by the subtending scales Y. 

 'y. Inflorescence stiff and erect, or at least with approximate 

 spikes Z. 

 Z. Spikes whitish or gray-green. 



Perigynia lance-ovate, 4-4.8 mm. long, nerveless on 



the inner face, golden-yellow at base . 

 Perigynia broad-ovate to suborbicular. 

 Perigynia strongly ribbed the length of the inner 

 face, 2 mm. broad 



^''SVroadef ' " ^''?'^^ """"""^ '" '''' •'''"'' 9- C. aWolutescens, 

 Z. Spikes bronze or ferruginous. 



Perigynia distinctly concave on the usually nerved 

 inner face ; achene 1 mm. broad . . ■ • 

 Perigynia flat or convex on the usually nerveless 

 inner face, very plump ; achene 2 mm. broad 

 r. Inflorescence flexuous, at least the lower spikes remote a. 

 a. Perigynia nerveless or only faintly short-nerved on the 

 inner face. . j 



Perigvnia ovate-lanceolate, one third as broad as , 



fong; achene 1mm. broad . . . • • 1. O. pratemts. 

 Perigynia ovate, half as broad as long ; achene 1.5 mm. 



broad 



a. Perigynia distinctly nerved on the inner face. 



Perigynia 2.8-4.4 mm. long, at most 2.4 mm. broad, 

 7-13-ribbed on the inner face, abruptly beaked. 

 Inflorescence of 4-9 spikes 6-10 mm. long ; peri- 

 gynia 2.8-4 mm. long ...••• 

 Inflorescence of^6-15 ^spikes 10-17 mm. long;^^ a foenea,^. perplexa. 



21. C. ieerantica. 



19. C. foenea. 



20. C. leporina. 

 23. C. adnata. 



22. O. aenea. 



19. a. 



perigynia 

 'nerved on ' the'inner"face,*'obscu"rely broad -beaked 14. C. silicea. 

 D. Bracts leaf-like, much prolonged, the lowest 1-2 dm. long; 



spikes crowded ; perigynia subulate 



C. Perigynia horizontally spreading or reflexed when mature, spongy 

 at base, with thin but scarcely winged margins b. 

 b. Spikes solitary and terminal, pistillate or staminate, or witn 



24. C. sychnocephala. 



flowers variously scattered. , . v, ^ ar 



Stoloniferous ; the fihform culms at most 3 dm. nigh, Irom nii- 

 form rootstocks 



25. G. gynocrates. 



Not stoloniferous; the mry culms 2-7 dm. high, in caespitose 



stools 2fa. 0. 6XIU8. 



&. Spikes 2-several c. ■, ^ ^ 



c. Perigvnia broadest at base ; beak rough or serrulate rf. 

 a Perigynia at most half as broad as long, finally yellowish, with 

 slender beak nearly equaling the body ; scales pointed e. 



