C¥PEEACEAE. 61 



New Jersey— Common. 



New Castle— Dixon 'a, etc. Frequent. 



22. Cypertjs Grayi Torr. M. p. 166. Barren sands near the coast. Sum- 



mer. 

 New Jersey — Common. 

 New Castle — Collins, Summit Bridge, Commons. 



23. Ctperus eohinatus (Ell.) "Wood. M. p. 166. Dry soil. 'Summer. 



Philadelphia— Ballast below Navy Yard, Porter (He.), Bartram's Gar- 

 den (P.). 



2. DTJLICHIUM L. C Richard. 



1. Dulichium arunmnaceum (L.) Britton. M. p. 167. Wet places. 

 Summer. 



3, ELEOCHABIS E. Br. Spike-Rush. 



Spikelet scarcely or not at all thicker than the culm. 

 Culm stout; spikelet mamy-flowered. 



Culm terete, nodose. 1. E. interstincta. 



Culm quadrangular, continuous. 2. E.' mutata. ' 



Culm slender, triangular, continuous; spikelets few-flowered, subulate. 



3. E. Eobbinsii. 

 Spikelet manifestly thicker than the culm. 



Style mostly 2-cleft; achene lenticular or biconvex. 



Upper sheath scarious, hyaline; plants perennial by slender root- 

 stocks. 4. A', olimacea. 

 Upper sheath truncate, oblique, or toothed, not scarious. 

 Annual, with fibrous roots. 



Spikelet ovoid or oblong; tubercle deltoid, acute. 



5. E. ovata. 

 Spikelet oblong-cylindric ; tubercle broad, low. ■« 



6. E. Engelmanni. 

 Perennial by horizontal rootstoeks. 



Tubercle flat-conic. 



Scape and spike stout. 7. E. palustris. 



Scape and spike slender. 8. E. glaucescens. 



Tubercle swollen, bulb-like ; : spikelet not thicker than the 

 scape. 9. E. Smallii. 



Style 3-cleft; achene 3-angled or turgid. 

 Achene reticulated or cancellate. 



Spikelet compressed; culm filiform. 10. E. dcicularis. 



Spikelet terete; culm slender. 11. E. tuberculosa. 



Achene smooth or papillose. 



Achene smooth, white; culms capillary. 12. E. microcarpa. 

 Achene papillose, brown, black, or yellow. 

 Tubercle depressed or short-conic. 



Achene 3-ribbed on the angles. 13. E. tricostata. 

 Achene obtuse-angled, not ribbed. 



Culm filiform ; scales obtuse. 14. E. tenuis. 

 Culm flat ; scale's acute. 15. E. acuminata. 



Tubercle subulate or narrowly, pyramidal. 



Culms filiform, wiry, densely tufted, 1-2.5 dm. long. 



16. E. intermedia. 

 Culms flattened, slender, 3-6 dm. long. 



17. E. rostellata. 



1. Eleocharis interstincta (Vahl.) R. & S. M. p. 168. Shallow water. 

 Summer. 

 Gloucester — Repaupo (He.). 



