(0.1-) 0.2-0.3 (-0.4) mm. long. E. arenicola Torr., E. Palmed Svens. 



In moist soil, in shallow water of streams and ponds and in wet granitic sands, 

 in Okla. (Roger Mills, Alfalfa, Grady, Johnston and Bryan cos.), essentially 

 throughout Tex. (rare in extreme e. and extreme w.), N. M. (Sandoval Co.) and 

 Ariz. (Coconino, Yavapai, Pima, Cochise and Santa Cruz cos.), spring (-summer); 

 cen. Mex. n. to Ore., Ida., N.M., Okla., the Gulf States and S.C; also s. Braz., 

 Urug. and Arg. 



32. Eleocharis fallax Weath. Fig. 205. 



Perennial much like E. macrostachya but styles 2- or 3-branched, the achenes 

 averaging smaller (body 1.2-1.7 mm. long and tubercle 0.2-0.5 mm. long) and the 

 body more distinctly and regularly punctate (much as in E. montevidensis) . 



Rare in (brackish?) mud, s.e. Tex. (collected once in Matagorda Co.), summer 

 (?); coastwise, Mass. to Tex.; Cuba. 



33. Eleocharis austrotexana M. C. Johnst. 



Densely tufted perennial (probably with short slender matted reddish rhizomes); 

 culms 30-45 cm. long, erect, 0.8-1.1 mm. thick, essentially terete, with 12 to 15 

 minute striae in dried specimens and very weak but complete transverse septa 2-3 

 mm. apart (otherwise hollow); sheaths 2-5 cm. long, tight, mostly reddish, apically 

 quite firm, truncate or only very slightly oblique and with a seta or mucro to 

 1 mm. long; spikelets lanceolate, acuminate, acute, 8-13 mm. long, of about 50 

 to 70 flowers; scales ovate and acute to broadly lanceolate, about 2 mm. long, 

 medially buffy-brown (midnerve paler) and membranous, marginally hyaline, whit- 

 ish; bristles about 6 to 8, pale-brown, translucent, inconspicuous, persistent, un- 

 equal, the longer ones about equaling the achenial body; style 3-branched; achenial 

 body obovoid-pyriform, 0.7-0.9 mm. long, obscurely trigonous (the 2 inner angles 

 definite, though not sharp, the abaxial one obscure), ripening through shades of 

 yellow to golden-brown, surficially nearly smooth, slightly lustrous (under very 

 high magnification punctulate-reticulate); tubercle depressed-pyramidal, about 0.2 

 mm. long and broad, slightly constricted basally. 



Rare in Rio Grande Plains and s.e. Tex., Apr.; endemic. 



34. Eleocharis compressa Sulliv. 



Rhizomatous perennial; rhizomes 2-4 (-6) mm. thick, usually short and forking, 

 forming dense thick mats; culms tufted along the rhizome, 9-20 cm. long, erect, 

 strongly compressed, 0.6-1 mm. broad in the flat dimension, several-striate on each 

 side; sheaths usually reddish basally, apically firm and truncate or only very 

 slightly oblique, with a mucro; spikelets ovoid to narrowly ovoid, 5-12 mm. long, 

 with 20 to 40 flowers; scales broadly lanceolate, the lower medial portion chestnut- 

 brown or chestnut-fuscous (the mid-nerve somewhat paler), the margins and the 

 long-attenuate sometimes bifid (split) apex translucent-scarious; bristles 1 to 5, 

 promptly deciduous, very short; style 3-branched; achenial body broadly obovoid, 

 turgid, obscurely trigonous, about 1 mm. long, ripening through yellow to a golden- 

 brown, surficially granular-roughened or reticulate (rougher than in the following 

 species but not as rough as in E. tenuis); tubercle 0.1-0.2 mm. long, depressed- 

 to globose-conic, usually slightly constructed basally. E. elliptica Kunth var. com- 

 pressa (Sulliv.) Drapalik & Mohlenbrock. 



Rare in loamy usually moist soil and in shallow water of ponds and streams 

 in Okla. (Latimer Co.) and in e. Tex. (San Augustine Co.), spring; most of n.e. 

 U.S.; also Ont., Sask., Ga., Okla. and Tex. 



35. Eleocharis acutisquamata Buckl. 



Rhizomatous perennial; rhizomes 2-4 (-6) mm. thick, usually short and forking, 

 forming dense thick mats; culms tufted along the rhizomes, 8-20 (-28) cm. long, 



399 



