Genus 



SEDGE FAMILY. 



3 2 7 



19. 



S. paludosus. 

 S. robustus. 



20. S. fluviatilis. 



Spikelets several, capitate or umbellate, large ; involucral leaves 2 or more. 

 Achene lenticular or plano-convex ; spikelets sessile or some stalked. 



Scales short-awned ; achene lenticular. 1 



Scales long-awned ; achene plano-convex. 

 Achene trigonous ; spikelets mostly long-stalked. 

 Achene sharply and nearly exactly trigonous. 

 Achene with one face broader than the other two. 



Achene obovoid-orbicular ; leaves i"-2" wide; spikelets ovoid. 21. S.Fernaldi. 



Achene obovoid ; leaves 4"-8" wide ; spikelets narrowly cylindric. 22. 5\ novae-angliae. 

 Spikelets very numerous in compound umbels or umbelled heads, small ; involucral leaves several ; 



tall sedges. 

 Bristles downwardly barbed ; spikelets in umbelled heads. 

 Spikelets ovoid or oblong, i}4"-2j4" long. 



Bristles equalling or slightly exceeding the achene ; leaves 3"-8" wide. 

 Style 3-clef t ; achene 3-angled ; bristles 6. 



Spikelets 3-8 in each head ; bristles barbed throughout ; scales obtuse. 



23. 5". sylvaticus. 

 Spikelets 8-20 in each head ; bristles not barbed below ; scales acute or awned. 



Plant dark green ; scales acute. 

 Plant pale ; scales rough-awned. 

 Style 2-cleft ; achene plano-convex ; bristles 4. 

 Bristles flexuous, twice as long as the achene ; leaves 2"-$' 

 Spikelets cylindric, 3"-$" long ; style 3-cleft. 

 Bristles smooth or slightly pubescent ; umbel mostly decompound. 

 Bristles shorter than or scarcely exceeding the scales. 

 Bristles about as long as the achene ; scales subacute. 

 Bristles much longer than the achene; scales mucronate. 

 Bristles much exserted beyond the scales when mature. 



wide. 



24. 



26, 



27. 



29. 

 30. 

 31. 



5 1 . atrovirens. 

 S. pallidas. 

 S. microcarpus. 

 S. polyphyllus. 

 S. Peckii. 



S. divaricatus. 

 S. lineatus. 

 S. cyperinus. 



i. Scirpus nanus Spreng. Dwarf Club-rush. Fig. 801. 



Scirpus nanus Spreng. Pug. 1: 4. 1815. 



Eleocharis pygmaea Torr. Ann. Lye. N. Y. 3 : 313. 1836. 



Annual, roots fibrous, culms filiform, flattened, 

 grooved, tufted, erect or ascending, 1'— 2' high, bearing 

 a scarious bladeless sheath near the base. Spikelet 

 solitary, terminal, ovoid-oblong, rather acute, 3-8-flow- 

 ered, i"-ii" long, not subtended by a bract; scales ovate 

 or lanceolate, pale green, the lower obtuse, the upper 

 subacute; bristles about 6, downwardly barbed, mostly 

 longer than the achene ; stamens 3 ; style 3-cleft ; achene 

 oblong, 3-angled, pale, pointed at each end, smooth. 



Muddy places in salt marshes, Cape Breton Island to 

 Florida and Texas, and about salt springs in New York, 

 Michigan and Minnesota. Also on the Pacific Coast of 

 North America and on the coasts of Europe, northern 

 Africa, Cuba and Mexico. July-Sept. 



2. Scirpus pauciflorus Lightf . Few-flowered Club- 

 rush. Fig. 802. 



Scirpus pauciflorus Lightf. Fl. Scot. 1078. 1777. 



Eleocharis pauciflorus Link, Hort. Berol. 1 : 284. 1827. 



Perennial by filiform rootstocks, culms very slender, 

 little tufted, 3-angled, grooved, leafless, 3'-io' tall, the 

 upper sheath truncate. Spikelet terminal, solitary, not 

 subtended by an involucral bract, oblong, compressed, 

 4-10-flowered, 2"-3" long, nearly 1" wide; scales brown 

 with lighter margins and midvein, lanceolate, acuminate; 

 bristles 2-6, hispid, as long as the achene or longer; 

 stamens 3 ; style 3-cleft ; achene obovoid-oblong, gray, 

 rather abruptly beaked, its surface finely retriculated. 



In wet soil, Anticosti to Maine, Ontario, western New York, 

 Illinois, Minnesota, British Columbia and California, south in 

 the Rocky Mountains to Colorado. Also in northern Europe 

 and Asia. July-Oct. 



