206 



CYPERACEAE (SEDGE FAMILY) 



14. G. silicea. 



13. C. BickneUii. 



Spikes brownish-white, of closely appressed ob- 

 scurely beaked Hrni perigynia .... 

 Spikes ferruginous: the abrupt slender beaks of 

 the perigynia with loosely ascending or spread- 

 ing tips " (12) C. horrnathodes, v. Richii 



Fi Inflorescence stiff (or, if flexuous, with brown or 

 ferruginous spikes) W. 

 W. Perigjnia 5.(i-T.T mm. long, very thin, scale-like, 



almost tran-iparent ; scales blunt 

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

 (when exceptionally longer in C. alata, with 

 aristate scales) X. 

 jr. Scales long-acuminate or aristate ; perigynia 

 4-5.5 mm. long; achenes oblong. 

 Spikes green or finally dull brown ; scales lance- 

 subulate ; perigynia obovate. 2.8-;3.7 mm. 

 broad, abruptly narrowed at base 

 Spikes becoming dark brown or ferruginous ; 

 perigynia 2.0-2.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. 



15. C. alata. 



16. C. fsuherecta. 



£. 



abruptly slender-beaked 

 Scales blunt or at most acutish. 

 Spikes gray-green or finally dull brown, 

 strongly appressed-ascending very 

 perigynia 3.5— t (very rarely 4.5) mm, 

 Spikes straw-colored or ferruginous, 



(12) C. hormathodes, v. Richii. 



^vith 

 firm 

 long 

 with 



9. C. alboluteacens. 



spreading-ascending perigynia 4— 5.5 mm. long. 



Inflorescence of 5-io mostly distinct spikes . 

 Inflorescence of 3-6 approximate spikes (IT) 

 B. Tips of the perigynia equaled b\' the subtending scales Y. 

 Y. Inflorescence stiff and erect, or at least with ajjproximate 

 spikes Z. 

 Z. Spikes whitish or grav -green. 



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



the inner fjice, golden-yellow at base . 

 Perigynia broad-ovate to suborbicular. 

 Perigynia strongly ribbed the length of the inner 



face, 2 mm. broad 



Perigynia nerveless or faintly nerved on the inner 



face, broader . . " 



Z. Spikes bronze or ferruginous. 



Perigynia distiiictly 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 

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



17. C.fesiucacea. 



C. festucacea, v. b'yevior. 



21. C. xerantica. 



19. C. foenea. 

 9. C. albolutescens. 



20. 

 23. 



C. leporina. 

 C. adusta. 



Perigynia nerveless or only faintly short-nerved on the 

 Inner face. 

 Perigynia ovate-lanceolate, one thu-d as broad as 



long; achene 1 mm. broad 



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



broad 



a. Perigynia distinctly nerved on the inner face. 



Perigynia 2.'>-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. S-4 mm. long 



Inflorescence of 6-15 spikes 10-17 mm. long: 



perigynia 3.5-4.4 mm. long . . . (Ifl) C. foenea, v. perple-ra 

 Perigynia 4-5.3 mm. long, 2.5-3 mm. broad, 8-5- 



nerved on the inner face, obscurely broad-beaked 14. 

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



spikes crowded ; perigynia subulate 24. 



C. Perigynia horizontally spreading or reflexed when mature, spongy 

 at base, with thin but scarcely winged margins b. 

 b. Spikes solitary and terminal, pistfllate or staminate, or with 

 flowers variously scattered. 

 Stoloniferous; the filiform culms at most 3 dm. high, from fiU- 



form rootstocks 25. 



Not 8tol(Hiiferous ; the wiry culms 2—7 dm. high, in caespitose 



stools 26. 



ft. Spikes 2-several c. 



c. Perigynia broadest at base ; beak rough or serrulate tl . 

 d. Perigynia at most half as broad as long, finally yellowi.sb. with 

 slender beak nearly equaling the body ; scales pointed 6. 



1. O. praiensis, 

 22. C. aenea. 



19. C. foenea. 



(7. silicea. 



C. sychnocephala. 



C. gynocrates, 

 C. exilis. 



