CYPERACEAE (SEDGE FAMILY) 



217 



Leaves 0.5-1.5 cm. broad 176. C.folliculata. 



Leaves 1.5-8.5 mm. broad 177. C. Michauxiana. 



pp. Teeth of the beak strongly refracted .... 178. C. subulata. 

 ff. Staminate spikes 2 or more rr. 



rr. Achene distinctly broader than long, its faces strongly con- 

 caved 171. C. gigantea. 



rr. Achene longer than broad, the faces flat or slightly convex . 

 **. Culm thick and spongy at base, generally smooth and 



bluntly angled above ; leaves prominently nodulose. 

 Perigynia flask-shaped, rather abruptly contracted to the 



beak, 3-6 mm. long. 



Stout; spikes cylindric, 2-10 cm. long .... 188. C.rostrata. 

 Slender ; spikes globose or short-cylindric, 1-2.5 cm. 



long (183) C. rostrata, v. ambigens. 



Perigynia tapering gradually to the beak, 0.5-1 cm. 



long (188) C. rostrata, v. utriculata. 



88. Culm scarcely spongy at base, sharp-angled above, often 



harsh ; leaves slightly if at all nodulose tt. 

 tt. Beak of the perigynia usually slightly roughened or 



serrulate. 



Pistillate spikes cylindric, 2.5-5 cm. long. l-1.5cra. thick 184. C. bullata. 

 Pistillate spikes globose to thick-cylindric, 1-4 cm. long, 



1.5-2 cm. thick (184) C. bullata, v. Greenii. 



tt. Beak of perigynia smooth uu. 



uu. Mature perigynia 5-6.5 mm. thick 185. C. Tuckermani. 



uu. Mature perigynia not more than 4 mm. thick w. 

 wo. Perigynia ascending, straight; leaves firm, 2-7 mm. 



wide. 



Perigynia bladdery inflated. 

 Perigynia ovoid-conic, tapering gradually to the 



beak 182. G. vesicaria. 



Perigynia rounded-ovoid, rather abruptly tapering 



to the beak. 

 Perigynia 6 mm. long. 



Spikes cylindric, 2-7 cm. long . . . (182) C. vesicaria, v. monile. 

 Spikes globose to short-cylindric, 1-2.5 cm. 



long (182) C. vesicaria, v. distenta. 



Perigynia 4-5 mm. long .... (182) C. vesicaria, v. jejuna. 

 Perigynia barely inflated, conic-subulate . (182) C. vesicaria, v. Raeana 



W. Perigynia retrorse or wide-spreading, slightly falcate ; 

 leaves soft and ribbon-like, 0.5-1 cm. wide . 



C. retrorsa. 



1. C. muskingum6nsis Schwein. Culms 1 m. or less 

 high, very leafy ; leaves subcordate at their junction with 

 the loose green sheaths, those of the 

 sterile shoots crowded and almost dis- 

 tichous ; inflorescence oblong, of 5-12 

 appressed-ascending pointed spikes ; 

 perigynia very thin and scale-like, 

 barely distended over the achenes. 

 Meadows, swamps, and wet woods, 

 O. to Man. and Mo. July, Aug. FIG. 

 340. 



2. C. scop^ria Schkuhr. Culms 

 0.2-1 m. high, mostly slender and 

 341 C scoparia erect ; leaves narrow (at most 3 mm. 

 wide}, shorter than the culm ; inflo- 

 rescence of 3-9 straw-colored or brownish mostly shining 

 and ascending approximate ovoid pointed spikes (0.5-1.5 

 cm. long) ; perigynia ^(rarely 4)-6.5 mm. 



S^W^lSH &. E5 ~0. -**,*-. 

 Ore., and southw. May-Aug. FIG. 341. Var. MONILIFORMIS 

 Tuckerm. Spikes scattered, the lowest remote. Less common. 

 Var. CONDNSA Fernald. Spikes spreading, crowded in a globose 

 or subglobose head. N. B. to Ont. and Ct. FIG. 342. 



3. C. tribuloides Wahlenb. Culms loose, 0.3-1 m. high, 

 sharply trigonous ; leaves soft and loose, 3-8 mm. broad, numer- 

 342. c. scoparia, ous, the upper often nearly or quite overtopping the culm, those 

 v. condensa. of the sterile shoots crowded and somewhat distichous; inflo- 



