145. Cyperaceae 315 



Menard Co., E. Hall in 1861 



C. richii (Fern.) Mack. 



18. Glumes acute; perigynia ncrxelcss or nearly so 



\cntrally. 



19. Perioynia 3-4 nun lono, widest above the 



middle; spikes 5-25, densely aggregated; 



peaty margin of oak woods near St. Anne, 



Kankakee Co., R. A. Schnridvr 1654 



C. cumulata (Bailey) Mack. 



19. Perigynia 4-5 mm long, widest at the middle; 

 spikes 2-5, ovoid, acute, yellowish-brown or 

 reddish-brown, 7-12 mm long: wet ground. 



Cook, Kankakee, and Will counties 



C. subrrecta (Olney) Britt. 



17. Leaf-sheaths conspicuously hyaline ventrally; spikes 5- 

 8 mm long, roundish, greenish; roadsides and open 



woods, comn:ion [C. molista Mack.] 



C. brevior (Dewey) Mack. 



16. Perigynia 5.5-6.5 mm long, 3-4 mm wide, flat, thin, trans- 

 lucent, prominently nerved on each face; dry soil in 

 the northern halt of 111 C. bickmllii Britt. 



GROUP III 



Stigmas 2; achenes lenticular; perigynia short-beaked or beakless; 

 spikes normally imisexual, i.e., the terminal spike commonly staminate, 

 the lower spikes entirely or mostly pistillate. 



1. Perigynia obovoid or subglobose, beakless, yellowish or brownish, 

 plump, nerved, about 2 mm in length, longer than the obtuse, 



pale brown glumes; wet ground. Lake Co C. aurva Nutt. 



1. Perigynia compressed, short-beaked, the beak less than 0.5 mm 

 long. 

 2. Midvein of pistillate glumes prolonged 5-10 mm beyond the 



glume; marshy ground, rare C. criiiita Lam. 



2. Midvein of pistillate glumes not conspicuously exserted. 

 3. Glumes obtuse, approximately equalling the perigynia. 



4. At least the lower pistillate spikes drooping; beak of pcri- 

 gynium twisted at maturity; in and along streams or 



rarely in swamps, s. Ill C. torta Boott 



4. All the pistillate spikes erect or ascending; beak of peri- 

 ,g\'nium not twisted. 

 5. Perigynium 2.7-3.2 mm long, strongly flattened; stems 

 strongly phyllopodic, the dried-up leaves of the pre- 

 vious year persistent; wet ground, n. 111. [C aquatilis 



of auth., not \Vahl.] C. substricta (Kiikenth.) Mack. 



5. Perigynium 2-2.7 nnn long; stems aphyllopodic; leaves 

 of the previous year not persistent; swamps in the n. 

 two-thirds of 111 C. stricta Lam. 



