182 



CYPERACEAE (SEDGE FAMILY) 



242. E. olivacea. 

 S pikelet x 2%. 

 Achene x 10. 



Spikelet x 

 Achene x 10. 



very pale and thin, 1.5-2.5 mm. long; achene often equaling the bristles, tipped 

 by a short slender conical tubercle. Wet places, Va. to Fla. (W. I., S. A.) 

 FIG. 241. 



5. E. olivacea Torr. Culms flatfish, grooved, diffusely tufted 

 on usually slender matted rootstocks, 2-15 cm. high; spikelet 

 oblong-ovoid, acutish, '20-3Q-flowered, 3-7 mm. long ; scales 

 ovate, obtuse, rather loosely imbricated, 2-3 mm. long, with a 

 slightly scarious margin ; achene obovoid, dull, green to blackish, 

 1 mm. long, shorter than the 6-8 bristles; 



tubercle capping \ of the summit of the 

 achene, saucer-shaped, tipped by a long conic- 

 subulate beak. Wet shores, Me. to Out., 

 s. to N. C., Pa., O., and Mich. FIG. 242. 



6. E. atropurpurea (Retz.) Kunth. Dwarf 



tufted annual ; culms capillary, arcuate, 3-7 243 E at ropurpurea 

 cm. long ; spikelet oblong-ovoid, 2-4 mm. 

 long; scales ovate, thin-membranaceous, blunt, dark brown, 

 with pale midrib and margin ; achene lenticular-obovoid, 

 lustrous, black, with a minute saucer-shaped tubercle ; bristles white, shorter 

 than the achene. Wet sand, "la." to Col., and southw. (Eurasia, W.I.) 

 FIG. 243. 



7. E. capitata (L.) R. Br. Culms terete, 0.3-3 dm. high; 

 spikelets ovoid to cylindric (3-5 mm. long), obtuse, 15-40-flowered ; 

 scales thickish, round-ovate, obtuse, pale brown, with green keel 

 and paler margins ; stamens 2 ; achene obovoid, black, about 

 equaling the 6-8 bristles, tipped with a flattened or 

 saucer-shaped tubercle. In sand or gravel near 



sloughs, Md. to Fla. and Tex. (W. I., S. A.) 

 FIG. 244. 



Var. dispar (E. J. Hill) Fernald. Scales purple- 

 brown ; achenes purple-black. (E. dispar E. J. 

 Hill.) Wet sand, Lake Co., Ind. 



8. E. diandra C. Wright. Erect or depressed ; 

 culms 0.1-5 dm. long ; spikelet ovoid, obtuse or acutish, 2-7 mm. 



long, 2-3.6 mm. thick; scales barely appressed, ovate to ovate- 245. E. diandra. 

 oblong, blunt, dull, pale brown, with prominent green midrib ; Spikelet x 2%! 

 achene obovoid or inverted-pyriforin, 1 mm. long. Sandy shores Achene x 10. 

 of the Androscoggin, Merrimac and Connecticut Rivers, and of 

 Oneida L. (N. Y.) Differing constantly from the next in its depressed tubercle 

 and paler scales, as well as in the absence of bristles. FIG. 245. 



9. E. ovata (Roth) R. & S. Erect or depressed ; culms 

 0.3-5 dm. long ; spikelet globose-ovoid to ovoid-cylindric, 

 obtuse, densely flowered, 2-7 inm. long, 2-4 mm. thick ; 

 scales oblong to narrowly ovate, obtuse, purple-brown, with 

 pale midrib and white scarious margin ; achene obovoid or 

 inverted-pyriform, about 1 mm. long. Wet places, N. B. to 

 Ct. and Mich. ; Ore. (Eurasia.) FIG. 246. 



10. E. obtusa (Willd.) Schultes. Simi- 

 lar ; culms 0.5-7 dm. high ; spikelet globose- 

 ovoid to ovoid-oblong, obtuse, 2-13 mm. 

 long, 2-5 mm. thick ; scales ovate-oblong to 

 suborbicular, with rounded tips, densely 



crowded in many ranks, dull brown; style 3(rarely 2*)-cleft ; 

 achene turbinate-obovoid with narrow base, pale brownish, 

 shining, shorter than the 6-8 bristles, slightly broader than 

 the short-deltoid acute and flattened tubercle. (E. ovata 

 Man. ed. 6.) Muddy places, N. S. to Ont., and southw.; 

 B. C. and Wash. FIG. 247. Like all the annual species, 

 very variable in size and habit. 



11. E. Engelmanni Steud. Similar; culms 1.5-3 din. 



244. E. capitata. 

 Spikelet x 2%. 

 Achene x 10. 



247. E. obtusa. 



Spikelet x -%. 

 Achene x 10. 



