Rare in water of lakes and ponds, in e. and s.e. Tex., summer-fall; Coastal 

 States, Mass. to Tex.; also Ind., Mich., Wise, and Mo. 



14. Eleocharis cellulosa Torr. Fig. 193. 



Tufted perennial; culms 5-8 dm. long, 2-5 mm. thick, erect, essentially terete 

 or irregularly compressed and striate; sheaths usually reddish, apically oblique, 

 membranous; spikelets cylindric, 19-36 cm. long, 3.5-5 mm. thick, with 50 to 90 

 flowers; scales broadly ovate to obovate, 5-6 mm. long, 3-3.5 mm. broad, medially 

 with a prominent midrib and subcartilaginous and stramineous, striate and brown- 

 penicillate, in texture passing laterally to chartaceous and finally to hyaline, in 

 color to pallid-buff, the distal margin finely white-hyaline, submarginally with a 

 thin brown line; bristles about 6, slender, mostly exceeding the achene and not 

 serrulate; style 3-branched; achene body biconvex, about 2 mm. long, brownish, 

 surficially distinctly cellular (the cells quadrangular, appearing as if embedded in 

 clear plastic), apically umbonate (forming a buttonlike base which is the podium 

 for and merges into the tubercle); tubercle conic-deltoid, 0.6-1 mm. long, 0.4-0.6 

 mm. broad, dark, not at all constricted basally but appearing as a continuation 

 of the umbo of the body although differing texturally (being noncellular). 



Infrequent in fresh-water and mud, occasionally forming mats in shallow 

 water, and in depressions, in the Tex. Edwards Plateau, rare in Rio Grande 

 Plains, exceedingly rare in e. Tex., spring-fall; Coastal States, N.C. to Tex.; 

 Mex.;W.I.;Berm. 



15. Eleocharis niacrostachya Britt. Creeping spike rush. Fig. 194. 



Rhizomatous perennial; rhizomes 1-2.5 mm. thick, often reddish; culms in tufts 

 along the rhizome, 18-50 cm. long, 0.9-3 mm. thick, erect, often appearing 

 slightly spongiose and irregularly sulcate on drying, occasionally compressed; 

 sheaths tight, apically truncate or very slightly oblique, very firm, in many speci- 

 mens mucronate, basally dark-reddish-brown; spikelets 8-25 mm. long, 3 mm. 

 thick, lanceolate or linear-lanceolate, acute, of 40 to 100 flowers; lowest 1 to 3 

 scales sterile, firm, obtuse, the lowest one sometimes completely encircling the 

 base of the spikelet; fertile scales lanceolate to broadly lanceolate, more or less 

 acute, about 3 mm. long, with a green or stramineous midrib (which does not 

 reach the apex), a firm buffy to castaneous lateral and subapical zone and a hya- 

 line margin and apex; bristles 7 or 8, brownish, unequal, the longest usually as 

 long as the tubercle; style 2-branched, the upper part promptly deciduous from 

 the base; achenial body obovate to pyriform, 1.2-1.8 mm. long, usually more 

 turgidly convex on one (abaxial) side than on the other, surficially nearly smooth 

 or very faintly reticulate-punctate in an open pattern, lustrous, ripening through 

 shades of yellow to golden-brown; tubercle 0.3-0.7 mm. long, conic to depressed 

 or even subglobular, grayish, texturally like pumice or rotted bone, usually about 

 half as broad as the body, basally constricted. Some workers refer these plants to 

 the Old World complex known by the name E. palustris (L.) R. & S., (?) E. calva 

 Torr., E. xyridiformis Fern. & Brack. 



Common and widespread in most of our area, in marshes, vernal pools, wet 

 meadows, ditches, flooded lands and alkaline mud, spring-summer; Minn, to III., 

 Mo., Kan., Okla. and Tex., w. to s. Alas., Calif, and s. to cen. Mex.; Col. 



16. Eleocharis flavescens (Poir.) Urban. Fig. 195. 



Perennial, often with elongate fleshy rhizomes 0.5-1 mm. thick; culms either 

 densely tufted or rising singly from the nodes of the rhizome, 4-35 cm. long, 0.3- 

 1 mm. thick, ascending, firm to flaccid, often sulcate when dried; sheaths apically 

 oblique, hyaline, fragile, promptly becoming loose and withered on drying; spike- 

 lets 3-6 mm. long, ovoid, acute or blunt, with 15 to 25 flowers at maturity (the 



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