A genus of about 300 species widely distributed in warm regions. Some love- 

 grasses are difficult to determine, the characters useful in distinguishing them 

 being subtle, quantitative ones which tend to grade from one species to another. 

 This probably is evidence of past hybridization and genetic contamination of 

 many species. 



1. Mat-forming annuals creeping by stolons (2) 



1. Not mat-forming (3) 



2(1). Flowers unisexual, staminate ones on some plants, pistillate on others; 

 lemmas about 3 mm. long, persistent on the rachilla....!. E. reptans. 



2. Flowers perfect; lemmas 1.5-2 mm. long, falling individually from the rachilla 



to expose the minute paleas which persist on the rachilla 



2. E. hypnoides. 



3(1). Spikelets (the lateral ones, not those terminal on the panicle branches) 

 subsessile, their pedicels averaging less than 1 mm. long (4) 



3. Spikelets (the lateral ones) with pedicels averaging more than 1 mm. long, 



often much more (5) 



4(3). Lemmas about 1 mm. long 8. E. glomerata. 



4. Lemmas 1.5-5.5 mm. long 4. E. cilianensis. 



5(3). Pedicels of individual spikelets 10-30 mm. long, averaging about 15-20 

 mm. long, rather stiff and straight 7. E. Elliottii. 



5. Pedicels of individual spikelets 1-18 mm. long, averaging usually less than 



10 mm. long, stiffish to weak and flexible (6) 



6(5). Perennial 6. E. hirsuta. 



6. Annuals (7) 



7(6). Lemmas about 1 mm. long 3. E. pilosa. 



7. Lemmas 1.5-2.5 mm. long 5. E. pectinacea. 



1. Eragrostis reptans (Michx.) Nees. 



Mat-forming annual, extensively creeping by stolons, rooting at the numerous 

 nodes; sheaths about 5 mm. long; blades 1-4 cm. long; panicles 1-3 cm. long, 

 about as thick, of several glomerules of spikelets, often subcapitate, of 2 sexes, 

 the staminate panicles on some plants, the pistillate on others; spikelets laterally 

 compressed, curvilinear, 4-17 mm. long, 6- to 32-flowered, the rachilla remaining 

 intact; lemmas often pubescent, about 3 mm. long, not falling individually from 

 the rachilla. Neeragrostis reptans (Michx.) Nicora. 



Locally abundant in swales and lake- and river-beds, and muddy shores of 

 lakes, streams and ponds, usually in tight clay-loam soil, in Okla. {Waterfall) 

 and in n.-cen., e. and s.e. Tex. and Rio Grande Plains, spring-fall; cen. U. S. 

 from S.D. e. to 111. and Ky. and s. to Coah. and Tam.; also Fla. 



2. Eragrostis hypnoides (Lam.)B.S.P. Fig. 86. 



Annual, creeping over small areas by short stolons; culms very slender and 

 short; sheaths and blades very short as in E. reptans; panicles often subcapitate 

 or occasionally elongate to interrupted-spikelike or even more open, diffusely 

 oblong, with short branches; pedicels 1-3 mm. long, capillary, somewhat flexuous; 

 spikelets approximate or even glomerulate, linear, 2-20 mm. long, 4- to 44- 

 flowered, the flowers all perfect, the rachilla remaining intact; lemmas lance- 

 ovate, 1.5-2 mm. long, falling individually (starting at the bottom of the spikelet) 

 to liberate the grains and to leave the minute paleas persistent on the rachilla. 



Locally abundant in swales, borrow ditches, on margin of ponds, sloughs and 

 streams, and on mud flats, streambars and banks, in Okla. (Pittsburg Co.), e. 

 and s.e. Tex., rare in coastal parts of Rio Grande Plains (Cameron Co.) and 

 N.M. (Taos Co.), spring-fall; widespread from s. Can. nearly throughout the 

 U.S. to Mex. and W.L; Arg. 



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