CYPERACEAE (^SEDGE FAMILY) 



183 



249. E. palustris. 

 Spikelet x 2. 

 Achene x 10. 



248. E. Engelmannl 

 Spikelet X 2%. 

 Achene x 10. 



or in wet grassy 

 (Eurasia.) Fig 

 Culms slender or 



big'h ; spikelet cylindric, 6-20 mm. long, 2-4 mm. thick, acutish ; scales cloee- 

 nppressed, brown; achenes with broad much flattened tubercle; bristles about 

 equaling the achene. — Local, Mass. to Mo. Fig. 2-48. Var. 

 DETONSA Gray. Bristles wanting or rudimentary. — More 

 frequent, Mass. to Neb., s. to Pa., Ind., and Ariz. 



12. E. palustris (L.) R. & S. Culms nearly terete, striate, 

 0.1-L5 m. high ; spikelet slender, sub- 

 cylindric, pointed, many-flowered ; scales 

 ovate-oblong, loosely imbricated, reddish- 

 brown with a broad and translucent 

 whitish margin and a greenish keel, the 

 upper acutish, the lowest rounded and 

 often enlarged ; achene obovoid, some- 

 what shining, crowned with a short ovate 

 or ovate-triangular flattened tubercle, 

 shorter than the usually 4 bristles. — 

 Very common and variable, either in 

 water, where it is rather stout and tall, 

 grounds, where it is slender and lower. 

 249. Var. glaucescens (Willd.) Gray. 



filiform ; tubercle narrower, acute, beak-like, sometimes half as long as the 

 achene. — With the type. Var. calva (Torr.) Gray. Bristles none ; tubercle 

 short, but narrower than in the type. — Local. Var. vigens 

 Bailey. Culms very stout, rigid ; achene more broadly obovoid. 

 — Lake margins, north w. 



13. E. acicularis (L.) R. & S. Culms finely capillary, 3-10 

 cm. high (becoming much elongate when submersed), more or 



less ^-angular; spikelet 2-6 mm. long; scales 

 ovate-oblong, rather obtuse (greenish with purple 

 sides) ; achenes obovate-oblong, only the lowest 

 maturing, with S-ribbed angles and 2-3 times as 

 many smaller intermediate ribs, also transversely 

 striate, longer than the 3-4 very fugacious bristles 

 cal-triangular. — Muddy shores, across the continent. (W. I., 

 Eurasia.) Fig. 250. 



14. E. W61fii Gray. Culms slender (2-3 dm. high), from very 

 small creeping rhizomes, 2-edged; spikelet slender-ovoid, acute, 

 0.5-1 cm. long; scales ovate-oblong, obtuse, scarious, pale purple ; 

 achene pyriform, shining, with 9 nearly equidistant obtuse ribs 

 having transverse wrinkles between them ; tubercle depressed, truncate, more 

 or less apiculate; bristles none. — Wet prairies. 111., Minn., and la. Fig. 251, 



15. E. t6rtilis (Link) Schultes. Culms tufted from fibrous 

 roots, sharply triangular, capillary, twisting when dry ; spike- 

 let turgid-ovoid, 3-6 mm. long, few-flowered ; scales firm- 

 persistent, ovate ; bristles stout, barbed, 

 as long as the striate and pitted-reticu- 

 late achene and its conic-beaked tuber- 

 cle.—^. J. to Fla. Fig. 252. 



16. E. tuberculbsa (Michx.) R. & S. 

 Similar; culms flattish, S:tv\?it% \ spike- 



"nwpvpd ? 



252. E. tortilis. 



250, E. acicularis. 

 Spikelet x 2. 

 Achene x 10. 



; tubercle coni- 



membranaceous, 



Spikelet X 2. 

 Achene x 10. 



E, tuberculosa. 

 Spikelet x 2. 

 Achene x 10. 



tubercle flattish - cap - shaped. — Wet 

 sandy soil, from Mass. along the coast 

 to Fla. Fig. 253. 



17. E. Torreyana Boeckl. Tufted culms capillary, 

 1-6 dm. high; spikelet small (2-5 mm. long), sometimes 

 proliferous, the one or more short new culms from the 

 axil of its lowest scale, which persists as an herbaceous 

 bract; scales thin, ovate, acutish, whitish-green and 

 brown ; achene tiny, white, with sharp angles and a short 



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