Cheeseman. — Revision of the X.Z. Species of CareX. 421 



A. Spikelets all androgynous ; female flowers above, male below. 

 Leaves usually flat; spikelets approximate, green or pale 



perigynia ovate, beaked, serrate . . . . . . . . 3. C. inversa. 



Leaves involute, wiry ; spikelets approximate, brown ; peri- 



gynia broadly ovate, not beaked, serrate 4. G. eolensoi. 



Leaves flat, grassy ; spikelets approximate, purplish-brown ; 



perigynia ovate, compressed, entire . . . . .. 5. G. parkeri. 



Leaves flat ; spikelets approximate, pale brown ; perigynia 



narrow-ovoid, margined, beak long, serrulate .. ..6. C.leporina. 

 Leaves narrow, keeled; spikelets spreading, close together 



or distant ; perigynia squarrose, ovate-lanceolate, corky 



at the base, nerved, beak long 7. C. echinata. 



B. Spikelets all androgynous ; male flowers above, female below. 

 Tufted, slender ; spikelets in a linear or oblong head £ to 1£ 



inch long ; perigynia pale, spreading, hardly nerved . . 8. C. muricata. 



Hardly tufted, slender ; spikelets in an ovoid head £ to 1 



inch long; perigynia dark brown, polished, nerved below 9. G. teretiuscula. 



Tufted, often very tall and stout ; spikelets many, in a nar- 

 row or loose panicle 6 to IS inches long; perigynia 

 ovoid, turgid, nerved or nearly smooth 10. C. paniculata. 



C. Spikelets some androgynous, others wholly pistillate or wholly 

 stammate, or inflorescence altogether dioecious. Perigynia narrow 

 lanceolate, very long beaked. 



Dioecious, or with few females in the male inflorescence, and 

 few males in the female ; leaves semi-terete, strict ; 

 spikelets in a linear head 1 inch long . . . . .. 11. G. viridis. 



Most of the spikelets wholly pistillate, the staminate flowers 

 few, and irregularly placed ; leaves keeled ; spikelets in 

 an open panicle 4 to 9 inches long . . . . .. 12. G. kaloides. 



Section III. — Spikelets separate, usually stalked, unisexual ; the male 

 spikelets constantly uppermost, rarely mixed with female flowers ; the lower 

 spikelets all female or with a few male flowers at the base or apex. (Sp. 

 13-40.) 



A. Stigmas 2. Female spikelets often wholly unisexual, the male 

 flowers, when present, usually at the top of the spikelet, rarely 



below. 

 From 6 to 18 inches high ; spikelets 3 to 6, short, erect ; 



glumes obtuse 13. (7. vulgaris. 



Tall, grassy, slender, 1 to 3 feet high ; spikelets 4 to 8, long ; 



glumes mucronate . . . . . . • ■ • • • • 1^- G. suodola. 



Tall, stout or slender, 1 to i feet high ; leaves often £ inch 



broad ; spikelets numerous, 8 to 25, long stalked and 



pendulous ; glumes awned . . . . . . • • . . 15. C. ternana. 



B. Stigmas 2. Female spikelets often wholly unisexual; the male 

 flowers, when present, usuaUy at the base of the spikelets, rarely 

 at the top. 



