392 CYPERACEiE. 



or hispid. Style 2 — 3 -cleft, bulbous at the base. Acbenium 

 lenticular or obtusely triangular. 



* Spike cylindric. Scales rigid, spirally arranged. Style Z-cleft. 



1. E . equisetoides Torr.: culm terete, remotely nodose, papillose ; scales 

 suborbicular-ovate, very obtuse or slightly pointed ; bristles 6, as long as 

 the obovate biconvex achenium ; tubercle conic-rostrate, acute. Scirp^is 

 equisetoides Ell. 



Bogs and in water. Near Lewiston, Del. S. to Geor. July. %. — Culm 

 18 — 24 inches liigh, slightly roughened with ramute papillae. Spike about an 

 inch long, rather acute. Scales with a narrow scarious margin. 



Equisetum-like Spike Rush. 



2. E. quadrangulata Broion : culm acutely and unequally quadrangular, 

 three of the sides concave, the other wider and flat; scales broad-ovate, 

 very obtuse ; bristles 6, as long as the obovate striate achenium ; tubercle 

 conic, compressed. Scirpus quadrangulatus Mich. 



Swamps and margins of rivers. Penn. to Car. and Louis. June. %. — 

 Rhizoma creeping. Culm 2 — 4 feet high, with purple sheaths at base. Spike 

 12 — 16 lines in length. Scales with a scarious margin, dotted with purple. 



Square-stalked Spike RusJi. 



** Spike avoid or oblong. Scales membranaceous, very numerous, iroegularhj 

 imbricated. Style mostly 2-cleft. 



3. E. palustris Brown : culm terete, striate, spongy ; spike oblong-lance- 

 olate ; scales somewhat obtuse, the two lowest large and empty ; bristles 

 3 — 6, hispid, longer than the lenticular smocth achenium. S:ir pus palus- 

 tris Linn. 



Marshes and low meadows. Arct. Amer, to Flor. W. to the Pacific Ocean. 

 July, Aug. %.. — Rhizoma creeping. Culm 1 — 2 feet high, erect, with three 

 sheaths at base. Spike 3 — 5 lines long, many-flowered. Scales fuscous in the 

 middle. Common Spike Rush. 



4. E. olivacea Torr. : culm fihform, compressed, sulcate, soft ; spike 

 ovoid, mostly somewhat obtuse, many-flowered ; scales ovate, obtuse, mem- 

 branaceous ; bristles 6 — 8, retrorsely hispid, nearly twice as long as the 

 obovoid lenticular achenium. Scirp^is intermedins Gray. ^ 



Wet sandy places. Mass. N. Y. and N. J. Aug. %. — Culms 6 — 8 inches 

 long, cespitose, erect or decumbent, often dwarfish and slender. Spikes 3 lines 

 long, 20 — 30-flowered. Achenium smooth, dark olive when ripe. 



Olive-fruited Spike Rush. 



5. E. rostellata Torr. : culm compressed, sulcate ; spike ovoid-lanceolate, 

 acute ; scales ovate, obtuse, loose, with a scarioue margin ; bristles 4 — 6, 

 longer than the biconvex shining achenium ; tubercle conic-rostrate, ( Torr. 

 N. Y. El.) Scirpus rostellatus Torr. Cyp. 



Penn-Yan, Yates County, N. Y. Torr. %.—Culm 12—18 inches high, 

 firm and tough, compressed, sulcate. Spike 12 — 15-flowered. Scales lio^ht brown. 

 Bristles hispid downward. Beaked SpUte Rush. 



6. E. intermedia Schultes : culm setaceous, diff'use, compressed, angulai 

 and sulcate ; spike ovoid-lanceolate, acute ; scales somewhat acute ; bris- 

 tles 6, longer than the obovoid compressed achenium ; style 3-cleft ; tubercle 

 distinct. Scirp^is iivtermedius Muhl. 



