530 CTPERACE^. (sedge FAMILY.) 



bracts long and leaf-like, with very short sheathing bases, much exceeding the 

 culm (about equal to it in No. 106) : staminaie spikes 1-5 



* Perigynia with a very short and thick beak, and with short and thick slightlj) 



spreading teeth. — Laci5stees. 



106. C. Striata, Michx. (not of ed. 1.) Sterile spikes 2-3, the upper- 

 most stalked ; fertile spikes 1-2, oblong, erect, remote, on very short stalks ; peri- 

 gynia ovoid, abruptly contracted into a slightly serrulate beak, longer than the point- 

 ed purple scale. (C. polymorpha, erf. 1.) — Wet places. New Jersey to Vir- 

 ginia, and southward. 



107. C. lacustris, Willd. Sterile spikes 2-5, the uppermost stalked; 

 fertile spikes 2-3, oblong-cylindrical, stout, erect, remote, nearly sessile, or the low- 

 est on a short stalk; perigynia oblong, but little exceeding the lanceolate awncd 

 scale; culm shai-ply triangular, rough; sheaths very short, smooth. (C. riparia, 

 Muhl., not of Curtis. ) — Swamps arid borders of lakes and rivers ; common. — 

 A robust species, 3° - 5° high, with leaves i' - 1' wide^ 



* * Perigynia viith an elongated tapering beak, and long widely spreading or recurved 



sharp and spine-like teeth. — AeistAt^. 

 t- Staminate spikes 2-5, some occasionally bearing a few fertile flowei'S. 



108. C. aristata, B. Brown. Fertile spikes 2-4, cylindrical, erect, re- 

 mote, the lower on partly exserted short stalks ; perigynia tapeiing from an ocoid 

 base into a deeply 2 forked beak, longer than the ovate-lanceolate awned scale ; 

 culm smooth ; sheaths and under surface of the leaves pubescent. ( C. atherodes, 

 Spreng.) — Lake shores and river-banks, N. New York to Michigan, and north- 

 westward. — Culm 2° - 3° high : leaves 2" - 3" wide. Fertile spikes 2' - 3' long, 

 often rather loosely flowered towards the base. 



109. C. trichoc^I'pa, Muhl. Fertile spikes 2-3, oblong-cylind>-ical, erect, 

 remote, one of them sometimes staminate at the apex, the lower on exserted 

 stalks, rather loosely flowered towards the base ; perigynia very hairy, shaped as 

 the last, longer than the ovate taper-pointed light-brown scale ; culm shai-ply 

 triangular, smooth except near the top, sheaths and under surface of the leaves 

 smooth. (C. striata, erf. 1, not of Michx.) — Marshes and lakes; common, es- 

 pecially northward. 



■•- ■<- Staminate spike solitary, with a filiform bract, occasionally bearing « few 

 fertile flowers towards the apex or base : fertile spikes 3-5, cylindrical, dense- 

 ly flowered, on long exserted and at length drooping stalks ; perigynia widely 

 spreading, rcflexed at maturity. 



110. C. COinosa, Boott. Fertile spikes large (If -2|' long, and ^'-|' 

 wide), the lowest sometimes very remote ; perigynia tapering from a stalked ovoid- 

 triangular base into a long deeply 2-forked beak, the sharp elongated teeth ividely spread- 

 ing or somewhat recurved; scales lanceolate with a long bristle-shaped awn 

 shorter than the mature fruit; culm rough and triqueti-ous. (C. furcata, £//., 

 not of Lapeyr. C. Pseudo-Cyperus, Schw. ^ Torr., Dew., S:-c., in part, not of i.) 

 — Wet places ; rather common. — A robust species 2° - 3° high, formerly con- 

 founded with the next, which it greatly resembles ; but it differs especially in 

 the larger fertile spikes, longer beak of the fruit, and the longer, smooth and 

 widely-spreading teeth, giving to the spikes a comose or bristly appearance. 



