CYPERACEJ3. (SEDGE FAMILY.) 369 



flattened tuberculate base persistent and mostly jointed upon the summit of 

 the turgid-triangular or lenticular akene. — Stems tufted, from matted or 

 creeping rootstocks, terete or angular, the base covered with closely appressed 

 sheaths : lower scale of the spikelet sometimes enlarged and bract-like. 



* Spike small and few-flowered, the scales somewhat distichous or only S-ranked: 



style 3-cleft and akene triangular. 

 ■i- Tubercle contracted at its junction with the akene. 



1. E. acicularis, B.. Br. Stems with fibrous roots and very slender run 

 ning rootstocks, usually setaceous, 1 to 8 inches high : spike 3 to 9-flowered : 

 scales acutish, more or less deeply tinged with brown : bristles 3 or 4, often 

 wanting: akene oblong-obovate, obscurely triangular and faintly ribbed on 

 the sides; tubercle broad, short and blunt. — On sandy or muddy stream- 

 banks across the continent. 



-f- -i- Tubercle continuous with the akene and not contracted at base. 



2. E. pauoiflora, Watson. Stems from slender running rootstocks, 3 to 

 8 inches high, striate i spike ovate-oblong : scales acute, dark brown : bristles 

 3 to 6, usually equalling the akene : akene oblong-obovate, obtusely triangular ; 

 tubercle rather stout, pyramidal, nearly a third as long as the akene. — Bot. 

 Calif, ii. 221. Scirpus pauciflorus, Lightfoot, Gray's Manual, 560. From 

 Colorado and Wyoming to the N. Atlantic States ; also in California. 



* * Spike terete, many-flowered : tubercle somewhat contracted at its junction with 



the akene : style 2-cleft and akene lenticular. 



3. E. palustris, B. Br. Stems usually slender, terete* striate, J to 4 feet 

 high : spike oblong-lanceolate to linear, acute, 3 to 12 lines long : scales obtuse or 

 the upper acutish, thin, brown with white margin and greenish keel : bristles 4, 

 about equalling the akene : akene obovate, turgid, smooth ; tubercle broad-deltoid, 

 acutish or acute, rarely acuminate. — Throughout the continent, and in most 

 parts of the Old World. 



4. E. olivacea, Torr. Stems very slender and spreading, 1 to 6 inches 

 high : spike ovate or oblong-ovate, 1 to 3 lines long : Scales obtuse, rather loosely 

 imbricated, purple with a green midrib : bristles 6 or 8, longer than the akene : 

 akene and tubercle as in the last. — Colorado, Montana, and Oregon ; also on 

 the Great Lakes and the Atlantic coast. 



5. E. COmpressa, Sulliv. Stem flat, striate, 1 to 2 feet high : spike ovate- 

 oblong, at length lanceolate, 4 to 7 lines long : scales acute, dark purple with 

 broad white pellucid margins: bristles 1 to 4 (or none), very slender and fragile, 

 shorter than or equalling the akene : akene obovate-pear-shaped, compressed ; tuber- 

 cle small, conical, pointed. — Gray's Manual, 858. 



6. PIMBEISTYLIS, Vahl. 



Scales closely imbricated around the rhachis. Styles 2 to 3-cleft, often flat- 

 tened and ciliate, somewhat dilated at base. Akene lenticular or triangular, 

 usually attenuate at base or substipitate. — In ours the style is 2-clef t and the 

 akene lenticular. 



1. F. spadicea, Vahl. Stems 1 to 2J feet high r from a perennial root, 

 rigid, as are the filiform convolute-channelled leaves : spikes ovate-oblong, becom- 



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