184 



CYPERACEAE (SBDGE FAMILY^ 



254. E. Torreyana. 

 Spikelet X 2. 

 Achene X 10. 



255. E. meknocarpi 

 Spikelet x 2. 

 Achene X 10. 



conical tubercle, which is hardly equaled by the 3-6 slendei 

 bristles. — Wet pine-barrens, etc., Ct. to Fla. Fig. 254. 



18. E. melanocirpa Torr. 'Tn.lieA,ii[:om.s, short thick caudex; 

 culms flattened, grooved, wiry, erect (2.5-7 dm. high), the close 

 basal sheaths with truncate mucronate tips; 

 spikelet cylindrical-ovoid, thick, obtuse, 

 densely many-flowered (7-15 mm. long) ; 

 scales closely many-ranked, roundish-ovate, very obtuse, 

 brownish, with broad scarious margins; achene glossy, obo- 

 void-top-shaped, obtusely triangular, the broad summit entirely 

 covered by the flat depressed tubercle, which is raised in the 

 center into a short abrupt triangular point ; bristles often 

 obsolete; achene soon blackish. — Wet sand, Mass. to Fla. ; 

 also n. Ind., where the culms are sometimes proliferous at 

 tip {Hill). (Bermuda.) Fig. 255. 



19. E. dlbida Torr. Tufted, from a slender creeping 

 base; culms slender, wiry, striate, 1-4 dm. high, the basal 



sheaths with very oblique tips; spikelet oylindric-ovoid, blunt, 4-9 

 mm. long ; scales obtuse, whitish to light brown, with narrow scari- 

 ous margin ; achenes smooth, not glossy, trigonous- 

 pyriform, 1 mm. long, contracted below the conic- 

 deltoid pale tubercle, and usually exceeded by the 

 reddish bristles. — Damp chiefly brackish soil, Md. 

 to Fla., etc. (Mex., W. I.) Fig. 256. 



20. E. tricostata Torr. Rootstock stout and 

 tough ; culms flattish (2-6 dm. high) ; spikelet soon 

 cylindrical, densely many-flowered (6-18 mm. long) ; 

 scales ovate, very obtuse, rusty brown, with broad 

 scarious margins ; achene obovoid, with 3 prominent 

 angles, minutely rough-wrinkled, crowned with a 

 thort-conical acute tubercle ; bristles none. — N. Y. to Fla. Fig. 257. 



21. E. tenuis (Willd.) Sohultes. Culms almost capillary, erect from running 

 rootstocks, i-angular (0.5-7 dm. high), the sides concave ; spika- 

 let ellipsoidal, acutish, 20-SO-flowered (3-10 mm. long) ; scales 

 ovate, obtuse, chestnut-purple, with a broad 

 scarious margin and green keel, the outer 2 or 

 3 mm. long; achene plump, obovoid, roughish- 

 lorinkled, 1-1.3 mm. long, crowned with a small 

 depressed tubercle, persistent after the fall of 

 the scales ; bristles J as long as the achene or 

 none. — Nld. to Man., and southw. June-Aug. 

 Fig. 2.58. 



22. E. acuminata (Muhl.) Nees. Similar ; 

 rootstock generally stouter and stifier ; culms 

 flat, striate, tufted, usually coarser ; scales 

 lance-ovate, the uppermost acute. (E. compressa 

 SuUiv.) — Wet places, oftenest in calcareous soil, N. Y. and 

 Ont, southw. Fig. 259. — Perhaps a variety of the last. 



23. E. nltida Fernald. Perennial, from slender rootstock ; 

 culms capillary, 4-angled, striate, 2-8 cm. high ; spikelet ovoid, 

 acutish, 2.5-4.5 mm. long, 1.5-2.5 mm. thick, 8-20-flowered ; scales 

 elliptic-oblong, with rounded tips, purplish-brown, with greenish 

 ribs and very narrow scarious margins, the lowermost 1-1.2 mm. 

 long; achenes whitish-straw-color, narrowly obovoid, sharply 

 trigonous, very minutely (under a lens) roughened, 0.7-1 mm. 

 long, the very narrow crown-like tubercle with a short point in 

 the middle. — Springy spots, valley of the Ottawa R., Can. (J. 

 Macoun). Early June. Fig. 260. 



24. E. iuterm^dia (Muhl.) Schultes. Culms capillary, striate-grooved, 

 densely tufted from fibrous roots, diffusely spreading or reclining {0.%-A dm 



25T. E. tricostata. 

 Spikelet x 2. 

 Achene x 10. 



258. E. tenuis. 

 Spikelet X 2. 

 Achene x lO. 

 CroBB-section of 

 culm X 5. 



259. E. acuminata. 



Spikelet x 2. 



Achene x 10. 



Cross-section of 



culm X 5. 



