496 CYPERACE.E. (SEDGE FAMILY.) 



surmounted by a flattish cap-shaped tubercle as large as itself. Wet sandy places, 

 Massachusetts, along the coast, to Virginia and southward. 



$ 2. ELE6CHARIS PROPER. Scales of the terete several - many-flowered spike 



membranaceous, and with a midrib or nerve, imbricated in more than three ranks. 



* Achenium lenticular (smooth) : style 2-cleft, in No. 4 commonly 3-cleJl: spike dense, 



many-flowered: culms rather slender, spongy. (ELEOGENUS, Nees.) 



4. E. Obtusa, Schultes. Culms nearly terete, tufted (8' -14' high) from 

 fibrous roots; spike globose-ovoid and with aye oblong, obtuse (dull brown); the 

 scales very obtuse and numerous (80-130), densely crowded in many ranks ; style 3- 

 ( rarely 2-) cleft; achenium obovate, shining, tumid-margined, about half the 

 length of the 6 bristles, crowned with a short and very broad flattened tubercle. 

 Muddy places ; everywhere common. 



5. E. olivacea, Torr. Culms flattish, grooved, diffusely tufted on slen 

 der matted rootstocks (2' -4' high); spike ovate, acutish, 20 - 30-flowered ; scales 

 ovate, obtuse, rather loosely imbricated in many ranks (purple with a green mid- 

 rib and slightly scarious margins) ; achenium obovate, dull, abruptly beaked 

 with a narrow tubercle, about half the length of the 6-8 bristles. Inundated 

 sandy soil, Massachusetts to New Jersey near the coast, and southward. 



6. E. palustris, R. Brown. Culms nearly terete, striate (l-2 high), 

 from running rootstocks; spike oblong-lanceolate, pointed, many-flowered; scales 

 ovate-oblong, loosely imbricated in several ranks, reddish-brown with a broad and 

 translucent whitish margin and a greenish keel, the upper acutish, the lowest 

 rounded and often enlarged ; achenium obovate, somewhat shining, crowned 

 with a short ovate or ovate-triangular flattened tubercle, shorter than the usually 

 4 bristles. Var. GLAUCESCENS (S. glaucescens, WiM.l): culms slender or fili- 

 form ; tubercle narrower and acute, beak-like, sometimes half the length of the 

 achenium. Var. CALVA (E. calva, Torr.)'. bristles wanting; tubercle short, 

 nearly as in the true E. palustris, but rather narrower (Watertown, New York, 

 Crawe). Very common, either in water, when it is pretty stout and tall; or in 

 low grassy grounds, when it is slender and lower. (Eu.) 



* * Achenium triangular : style 3-cleft : bristles sometimes few and fragile or alto- 

 gether wanting. (SciRpfoiUM, Nees, nearly.) 

 - Spike much broader than thefllifonn or slender culm : scales imbricated in several 



ranks, brownish or purplish with scarious whitish margins, l^nerved. 

 - Bristles 4-6, longer than the achenium, stout and bearded downward. 



7. E. I'OStellata, Torr. Culms flattened and striate-grooved, wiry, erect 

 (l-2 high), the sheath transversely truncate; spike ovoid-lanceolate, acute, 12- 

 ZQ-flowered ; scales ovate, obtuse, rather rigid (light brown) ; achenium smooth, 

 obovate-triangular, narrowed into the confluent pyramidal tubercle, which is 

 overtopped by the 4-6 bristles. Marshes, Rhode Island (Olney), Penn Yan, 

 New York (Sartwell), and Michigan. Allied to S. multicaulis of Eu. 



8. E. intermedia, Schultes. Culms capillary, wiry, striate-grooved, 

 densely tufted from fibrous roots, diffusely spreading or reclining (6' -12' long) ; 

 spike oblong-ovate, acutish, loosely W-lS-flowered (2" -3" long); scales oblong, 

 obtuse, green-keeled, the sides purplish-brown ; achecium smooth, obovoid with 



