216 



CYPERACEAE (SEDGE FAMILY) 



Perigynia obscurely ribbed (158) C. trichocarpa, v. Dewyi. 



Perigynia prominently ribbed. 



Sheaths hairy (158) C. trichocarpa, v. urixtnfu. 



Sheaths glabrous (158) C. trichocarpa, v. imberbix. 



bb. Perigynia thin and papery, usually more or less inflated ff. 



ff. Staminate spike solitary or none or the terminal only partly 



"&. 



staminate (rarely a very short secondary spike at the base 

 of the other) gg. 

 gg. Leaves involute-filiform ; perigynia broadly conic-ovoid, 5-6 



mm. loi 



gg. Leaves flat 



Mi. Perigynia obconic or broadly obovoid, truncate or abruptly 

 rounded above to long subulate beaks ; terminal spike 

 often mostly pistillate. 

 Perigynia longer than the scales. 

 Pistillate scales subulate-tipped or awned 



Pistillate scales blunt 



Perigynia shorter than the rough-awned scales . 

 Mi. Perigynia from subulate to ovoid or globose, if abruptly 



beaked the terminal spike staminate ii. 

 ii. Pistillate spikes oblong-cylindric or narrower jj. 

 jj. Perigynia scarcely inflated, rigid, lance-subulate, slender- 

 stipitate, with prominent rigid crowded ribs, soon 

 retrorse. 



Teeth of the perigynia nearly parallel .... 

 Teeth of the perigynia strongly divergent 

 jj. Perigynia inflated, if stipitate 



156. C. oUgosperma. 



161. C. squarrosa. 



162. C. typhinoides. 



163. C. Frankii. 



164. C. Pseudo-Cyperus. 



165. C. comosd. 



large and bladder-like kk. 

 kk. Mature perigynia less'than 12 mm. long 11. 



II. Pistillate scales mostly with thin serrulate awns ; 



perigynia not falcate mm. 

 mm. Staminate scales with rough awns ; plants 



caespitose. 

 Perigynia slightly inflated, narrowly conic; 



achenes obovoid 166. C. hystericina. 



Perigynia with bladdery-inflated subglobose 

 bodies and abrupt beaks ; achenes narrowly 

 ellipsoid-ovoid. 

 Pistillate spikes 1.5-2 cm. thick ; perigynia 7-10 



mm. long 167. C. lurida. 



Pistillate spikes 1-1.3 cm. thick ; perigynia 5-7 



mm. long (167) C. lurida, v. gradlis. 



mm. Staminate scales smooth, scarcely if at all awned ; 



plant loosely stoloniferous .... 168. C. Schwcinitstii. 

 II. Pistillate scales smooth, or only the lowest 



serrulate nn. 

 nn. Plant caespitose, forming tussocks ; perigynia 



somewhat falcate. 

 Spikes mostly clustered and sessile at the tip of 



the culms ; perigynia retrorse. 



Perigynia 8-10 mm. long .... 169. C. retrorsa. 



Perigynia 5-6 mm. long . . . (169) C. retrorsa, v. Robinsonii. 

 Spikes scattered, mostly long-peduncled. 



Perigynia wide-spreading or retrorse . (169) C. retrorsa, v. Hartii. 

 Perigynia ascending . . . (169) C. retrorxa, v. Macoitnii. 

 nn. Plant not caespitose, the culms solitary from slen- 

 der rootstocks ; perigynia not falcate . . 170. C. Halei. 



kk. Mature perigynia more than 12 mm. long. 



Achene rhomboid-ovoid, the angles prominently 



nipple-tipped 



Achene narrowly ellipsoid-ovoid, the angles scarcely 

 nipple-tipped. 



" illatr 



172. C. Inpuliformis. 



173. C. I a 1 1 n I i n ti. 



167. <'.lnri<lu. 



Pistillate spikes mostly crowded, sessile or sub- 

 sessile ........ 



Pistillate spikes mostly peduncled, the lowermost 



remote ...... (173) <'. Iitpnlinu. \. /;/ //nci/fdfd. 



ii. Pistillate spikes globose or subglobose oo. 

 oo. Staminate scales prolonged into rough thin awns 

 oo. Staminate scales smooth /,/>. 

 ji/i. Teeth of the beak erect or ascending qq. 

 </i/. Mature prrigynia trrccn. 



IVriirvnia elongate rhomboid, ouneate at b; 

 Pmgvnta glabrous ...... 174. C. Grai/i. 



IVrii/yni.-i liN|.idu]iis ..... (174^ <'. ffnii/i. v. 



Perigynia ovoid to narrowly conic, rounded at 



DAM. 



IVriirv nia ovoid conic, half as broad as long . 17. r >. <\ in1.ume.xcen*. 

 IVriVynia I.-IIK-.- -conic, one fourth to one third 



a> broad a-^ lung . . . (175) C. intumescens, v. fernaldii. 

 qq. Mature perigynia straw-colored. 



