164 



CYPERACEAE 



I. 5. nanus. 



S. planifolius. 

 S. subterminalis. 



Conn. Common in the north, rare or wanting southward. 

 N. Y. Westchester Co., increasing northward. 

 N. J. Bergen and Morris counties, increasing northward. 

 Pa. Pocono Summit, Monroe Co. 



Tertiary, o: Cretaceous, o: Older Formations, increasing north- 

 ward. Not south of the moraine. 1 17-153 days. Sea level- 

 3,900 ft. 



6. E. virginicum L. In bogs: Newf. to Man., south to Fla. and 



Neb. 



Throughout the range, more common in the bogs of the pine- 

 barrens and the mountains northward than in the intervening 

 territory. 



6. Scirpus L. 



Spikelet solitary, terminal. 

 Involucral bract wanting. 

 Involucral bract present, erect. 



Bract shorter than or but little exceeding the spikelet; 



plants not aquatic. 

 Bract at least twice as long as the spikelet ; plant aquatic. 

 Spikelets normally more than one, usually several or numerous, 

 often appearing lateral; involucral bract only one. 

 Spikelets few, 1-12, appearing lateral. 



Culms not sharply 3-angled; achene plano-convex; 



annual. 

 Culms sharply 3-angled; perennials. 



Achene plano-convex; bristles shorter than or equal- 

 ling the achene. 

 Spikelets acute, overtopped by the involucral 



bract. 

 Spikelets obtuse; involucral bract short, stout. 

 Achene 3-angled, ridged on the back. 



Bristles longer than the achene; involucral leaf 



erect. 

 Bristles as long as the achene; involucral leaf 

 abruptly bent. 

 Spikelets several or numerous, umbelled; tall sedges. 

 Style 2-cleft; achene lenticular. 

 Style 3-cleft; achene trigonous. 

 Spikelets several, capitate or umbellate, large; 

 2 or more. 

 Achene lenticular or plano-convex. 



Scales short-awned; achene lenticular 

 Scales long-awned; achene plano-convex. 

 Achene trigonous. 



Achene sharply and nearly exactly trigonous. 

 Achene with one face broader than the other two. 

 Spikelets very numerous in compound umbels or umbelled heads; 

 involucral leaves several; tall sedges. 



4. 5. debilis. 



5. 5. americanus. 



6. S. Olneyi. 



7. 5. Torreyi. 



13. S. fluviatilis. 



14. 5. novae-angliae. 



