strongly depressed-pyramidal, 0.1-0.2 mm. long, slightly constricted basally. 



Infrequent in moist or wet sand, wet forested areas, along ditches and in wet 

 mud along sloughs, in Okla. (Payne Co.) and e. Tex., rare in s.e. Tex., spring; 

 temp. e. N.A., w. to 111., Mo., Okla. and Tex. (the var. verrucosa in the w. part 

 of that distribution area). 



29. Eleocharis cylindrica Buckl. 



Rhizomatous perennial; rhizomes slender (1-2 mm. thick); culms 15-30 cm. 

 long, 0.4-0.5 mm. thick, about 4-sulcate and -angled, erect; sheaths faintly 

 reddish-brown basally. apically firm, truncate or very slightly oblique, mucronate; 

 spikelets linear-cylindric, 8-17 mm. long, 2-2.5 mm. thick, acute, of 50 to 60 

 flowers; scales about 2 mm. long, ovate, acute, medially thin-membranous, brown 

 (the midnerve pale), marginally white-hyaline, slightly convex abaxially; bristles 

 pale-brown, 0.05-0.1 mm. long, extremely inconspicuous; style 3-branched; 

 achenial body 0.6-0.8 (-1 ) mm. long, obovoid, strongly and obviously trigonous 

 (the sides slightly concave, the angles prominent but not sharp), ripening through 

 canary-yellow to golden-brown or dark-brown, essentially smooth and satiny, 

 apically conspicuously and abruptly narrowed to a short cylindric pedestal; 

 tubercle depressed-pyramidal, about 0.1 mm. long and about as wide or pyramidal 

 and about 0.3 mm. long. 



Rare, probably in shallow water or calcareous mud, in Tex. Plains Country 

 (Lubbock Co.) and Trans-Pecos (Presidio Co.), June-July; endemic, to be sought 

 in N.M. and Chih. 



30. Eleocharis Parishii Britt. Fig. 203. 



Perennial (or sometimes annual?) with slender creeping reddish rhizomes; 

 culms slender, striate, erect, 1-3 dm. tall, in fascicles or tufted; leaf sheaths 

 reddish-brown at base, usually becoming straw-colored at the obliquely truncate 

 apex, usually with a minute tooth; spikelets linear-lanceolate, acute, 10-15 mm. 

 long, many-flowered; scales ovate-oblong, acute to obtuse, chestnut-brown or 

 dark-brown, with a short hyaline tip; bristles 6 or 7, as long as to longer or 

 shorter than the achene; style trifid; achene trigonous, ellipsoid or obovoid, yellow 

 to light-brown, smooth or faintly reticulate under magnification; tubercle short- 

 subulate to conic. 



Moist soil, wet meadows or rooted in shallow water to form small mats in 

 N.M. (Grant and Valencia cos.) and Ariz, (widely distributed); Ore. to N.M., 

 Ariz., Calif, and n. Mex. 



31. Eleocharis tnontevidensis Kunth. Fig. 204. 



Rhizomatous perennial; rhizomes extensive, 1-2 (-2.5) mm. thick, usually dark- 

 reddish; culms 1-5 dm. long, 0.4-1 mm. thick, erect, rather soft, sometimes slightly 

 compressed, in pressed specimens often irregularly sulcate and showing incom- 

 plete and weak septa; sheaths basally dark-reddish, apically quite firm, truncate 

 or only very slightly oblique and weakly mucronate; spikelets very variable in 

 shape, from globular to cylindric or ovoid to elliptic, apically blunt, 3-14 mm. long, 

 with 24 to 70 (to 110) flowers; scales mostly oblong to oblong-ovate. 2-3 mm. 

 long, obtuse to slightly emarginate, the median portion membranous and brownish 

 to atrocastaneous (with or without a paler midnerve), marginally scarious, often 

 somewhat convex abaxially, concave adaxially (this true even before the achenes 

 mature, so the spikelets appear filled out soon after anthesis); bristles 4 to 6. some 

 of them usually equaling the tubercle; style 3-branched; achenial body obovoid 

 to pyriform-obovoid. (0.8-) 0.9-1.1 (-1.2) mm. long, turgid, obscurely trigonous, 

 ripening through shades of yellow to golden-brown or even dark-brown, punctuate- 

 reticulatc surficially (varying from as rough as in E. compressa to nearly smooth 

 as in the plant called E. Palmeri), lustrous; tubercle precisely to irregularly conic, 



396 



