FERNALD. CARICES OF SECTION HYPARRHENAE. 467 



2. Terminal spikelet without conspicuous clavate base : perigynia 

 obscurely beaked, brown-tinged, exceeding the blunt scales : 

 culms sharply angled, harsh and stiff : leaves flat, erect 



(41) C. heleonastes. 

 Perigynia at most 1.5 mm. long, oblong-cylindric, plump, nerveless, 

 beakless or with a very short broad truncate beak :. culms wiry : 

 spike linear-cylindric, dull brown (37) C. elachijcarpa. 



SYNOPSIS OF SPECIES. 



Ovales, Kunth. Perigynia ascending or slightly spreading (when 

 horizontally spreading, always with winged margins), with thin or winged 

 margins, mostly with concave inner faces when mature. 



§ Ovales proper. Bracts, when present, setaceous, or, if broader, 

 only once to twice longer than the spike. 



* Mature perigynia one-fourth to one-third (.24 to .36) as broad as long. 



-<- Perigynia extremely thin and scale-like, barely distended over the achenes. 



++ Perigynia 7 to 10 (average 8.3) mm. long. 



1. C. muskingumensis, Schweinitz. — Figs. 1, 2. — Culms 1 m. or 

 less tall, very leafy : the loose flat leaves subcordate at their junction 

 with the loose green sheaths ; those of the sterile shoots crowded and 

 almost distichous : spike oblong, of 5 to 12 appressed-ascending oblong- 

 cylindric pointed spikelets 1.5 to 2.5 cm. long. — Ann. Lye. N. Y. i. 66; 

 Dewey, Am. Jour. Sci. x. 281 ; Bailey in Gray, Man. ed. 6, 620; Britton 

 in Britton & Brown, 111. Fl. i. 355, fig. 861. C. arida, Schweiii. and 

 Torr. Ann. Lye. N. Y. i. 312, t. xxiv. fig. 2; Carey in Gray, Man. 

 545; Boott, 111. i. 20, t. 54; Boeckeler, Linnaea, xxxix. 112; Bailey, 

 Proc. Am. Acad. xxii. 147 ; Macoun, Cat. Can. PL ii. 129. C. scoparia, 

 Torr. Ann. Lye. N. Y. iii. 394, in part, not Schkuhr. C. scoparia, var. 

 muskingumensis, Tuck. Enum. Meth. 8, 17. — Meadows, swamps, and 

 wet woods, Ohio to Manitoba and Missouri. July, August. 



*+ ++ Perigynia at most 6.5 (very rarely 7) mm. long. 

 = Perigynia 5 to 6.5 (average 5.7) mm. long. 



2. C. scoparia, Schkuhr. — Figs. 3, 4. — Culms 0.2 to 1 m. high, 

 mostly slender and erect : leaves narrow (at most 3 mm. wide), shorter 

 than the culm: spike oblong-ovoid to subcylindric, of 3 to 9 straw- 

 colored or brownish mostly shining and ascending ovoid pointed spikelets 

 0.5 to 1.5 cm. long. — Schkuhr in Willd. Sp. iv. 230, & Riedgr. 



