64 FLOBA OF PHILADELPHIA. 



Bristles downwardly barbed, about equalling the achene. i 



4. S. debilis. 

 Bristles minute or wanting. 5. S. Smithii. 



Culms sharply 3 : angled; plants perennial' by rootstoeks. 



Achene plano-convex, bristles shorter than or equalling the 

 achene. , 

 Spikelets acute, much overtopped by the slender involucral 



leaf; scales awned. 6. S. Americanus. 



Spikelets obtuse; involucral leaf short, stoutf; scales 

 mucronulate. 7... 8. Olneyi. 



Achene 3-angled, ridged on the back. i 8. S. mucronatus. 

 Spikelets several or numerous, umbelled; tall sedges'. 



. ,„ ,- ■ : 9. S. lacustris. 



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

 Achene lenticular or plano-convex; spikelets capitate. 



10. S. rooustus. 

 Achene sharply 3-angled; spikelets umbellate. 11. S. fluviatilis. 



Spikelets very numerous in compound umbels or umbelled heads, small; in- 

 volucral leaves several ; tall sedges, , 

 Bristles downwardly barbed; spikelets in umbelled heads. 



Bristles equalling or slightly exceeding the aohene; leaves 6-16 mm. 

 wide. 

 Style 3-cleft; achene 3-angled; bristles 6. 



Spikelets 3-8 in each head; bristles barbed throughout; 



scales obtuse. , 12. 8. sylvatieus. 



Spikelets 8-20 in each head; bristles not barbed below; 

 scales acute. 13. 8. atrovirens. 



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



14. 8. microcarpus. 

 Bristles flexuous, twice as long as the achene; leaves 4-6 mm. 

 wide. 15. S. polyphyllus. 



Bristles smooth or slightly pubescent; umbel mostly decompound. 



16. 8. cyperinus. 



1. Sciepus nanus Spreng. M. p. 176. Brackish marshes. Summer. 



New Jersey — Frequent. 



2. Sciepus planifolius Muhl. M. p. 176. Woods and thickets. Summer. 



Philadelphia— Byberi y, Mart. (B. C), Old York Eoad (Te.), "Wissa- 

 hickon (VP.). BueTcs — Eock Hill (Fr.). Montgomery — Green Lane 

 (VP.). Delaware— Ithan 's Bridge, Dr. Geo. Smith (Fu.) (B. Sm.), Rad- 

 nor, Castle Eock (VP.). Chester— (P.): Lancaster— Lancaster (Kr.). 

 Berks— (P.). Northampton— Easton, Porter (B. C). 



Gloucester — Mullica Hill (C), Mickleton (He.), Swedesboro (Li.). 

 .Mercer— Princeton (C). 



New Castle— General and frequent. 



3. Sciepus subterminalis Torr. M. p. 176. Slow streams and ponds. 



Summer. 

 Burlington — Batsto, Quaker Bridge (C), Brown Mills, West Creek 

 (Te.). : Camden— Longacoming (C), near Cedar Brook (VP.). Glouces- 

 ter — Swedesboro, Eepaupo (Li.). Atlantic — Hammonton (Fr.), Mill 

 ' Pond near Atlantic City (He.), Bakersville (Li.). Ocean — Toms Eiver 

 (C.), Forked Biver (He.). 



4. Sciepus debilis Pursh. M. p. 177. Swamps. Summer. 



Philadelphia — Byberry, Mart. (B. C): Bucks — Eock Hill (Fr.). 

 Montgomery — ( P. ) . Delaware — Ehbads ' Swamp ( Fu. ) , Eidley Creek neaT 

 Media ■ (B. Sm.). , Chester— (P.). ' Lancaster— (P.). Lehigh— (P.). 

 Northampton — Easton, Porter (B. C). 



