194 



CYPERACEAE (SEDGE FAMILYJ) 



298. 8. atrovirens. 



cylindric, 3.5-8 (rarely 10) mm. long, in glomerules of 10-30 ; scales 1.5-2 mm. 

 long; bristles sparsely and strongly barbed, nearly straight, as long as the 



conspicuously pointed and obovoid-oblong trigonous achene. 



Meadows and bogs, Me. to Sask., s. to Ga. and Mo. Fr. 



late July, Aug. FIG. 298. Var. PYCNOCEPHALTJS Fernald. 



Rays abbreviated ; glomerules crowded in a dense irregular 



head. Flats of the Mohawk R., N. Y., local (Haberer). 



26. S. pallidus (Britton) Fernald. Similar ; leaves very 

 pale; spikelets pale brown, very numerous in irregular 

 glomerules ; scales 2-3 mm. long, with the conspicuous pale 

 midribs prolonged into long setulose awns. (S. atrovirens, 

 var. Britton. ) Man. to Kan. and the Rocky 



Mts. Fr. July. FIG. 299. 



27. S. georgianus Harper. Slender, 3-12 



dm. high, bright green ; leaves smooth, rarely 299. s. pallidus. 



nodulose below, numerous, crowded at base, 

 0.5-1 cm. broad, the ribs 0.15-0.2 mm. apart ; spikelets 2-4 mm. long, numerous 

 in the glomerules; the greenish-brown or rufescent scales mucronate, 1-1.5 mm. 



long, slightly exceeding the ellipsoid achenes. Que. to 



Mich., Ga., and Ark. Fr. July. Occasionally proliferous. 



28. S. polyphyllus Vahl. Culm usually very leafy; 

 spikelets yellow-brown or reddish, ovoid, 2.5-3 mm. long, 

 clustered 3-8 together in small heads on the short ultimate 

 divisions of the open decompound umbel ; scales rounded, 

 mucronate, 1-1.5 mm. long, about equaling the broadly 

 obovoid short-tipped achene ; bristles 6, usually twice 

 bent, about twice the length of the achene. Swamps and 

 borders of ponds, w. N. E. to Ga., w. to Minn, and Ark. 

 July-Sept. Often proliferous. FIG. 300. Var. MACROS- 



9nf> *4 rwiivnViviine TACHYS xSoecKi. opiKeiets cyimdnc, 



dOO. 8. polyphyllus. ;L oca l Q^ an( J NY 



29. S. divaricatus Ell.' Slender, weak, 0.5-1.5 m. high; 

 leaves very numerous, deep green, soft and smooth, 4-10 mm. 

 wide ; inflorescence loose, often proliferous, with elongated 

 widely divergent flexuous rays; spikelets mostly pediceled, 

 very slender, cylindric, at first 3 or 4 mm. long, the axis 

 elongating to 1 cm., 1-2 mm. thick ; scales whitish or pale 

 brown, blunt, incurved, with broad green midrib ; achene 

 firm, sharply trigonous, ovoid, apicu- 

 late. Swamps, etc., Va. to Mo., and 

 southw. June- Aug. FIG. 301. 



30. S. lineatus Michx. Culms re- 

 motely leafy, 0.5-1.5 m. high ; leaves 

 linear, flat, pale green, stiff, rather 

 broad (0.5-1 cm. wide), rough on the 

 margins ; involucre and involucels pale 

 brown at base ; umbels terminal and 

 sometimes axillary, loose, 0.5-2 dm. 

 high, subsecund, the terminal with a 

 1-3-leaved involucre much shorter than the long slender 

 ascending, nodding-tipped rays; spikelets oblong, becom- 

 ing cylindrical (0.5-1 cm. long), on thread-like drooping 

 pedicels; scales pale brown, ovate, green-keeled, pointed, the tips ascending, not 

 oppressed; achene firm, brown, sharp-pointed. (Eriophorum B. & H.) Low 

 grounds, Vt. to Ga., and westw. June-Aug. FIG. 302. 



31. S. PSckii Britton. Culms slender, 0.8-1.7 m. high ; leaves pale green, 

 5-9 mm. broad, the margins scabrous; involucre and involucels blackish at 

 base; inflorescence 0.5-2 dm. high, the 2-5 longest stiff rays ascending, the 

 others shorter, ascending or divergent, the tips scarcely drooping; spikelets 

 oblong-cylindric, 5-9 mm. long, mostly sessile or subsessile in glomerules of 



S. divaricatus. 



302. S. lineatus. 



