48 CYPERACEAE. 



Stamens 2-3. Style 2-cleft and achene lenticular or biconvex, or 3-eleft and 

 achene 3-angled, but sometimes with very obtuse angles and appearing turgid. 

 Base of the style persistent on the summit of the achene, forming a terminal 

 tubercle. [Greek, referring to the growth of most of the species in marshy 

 ground.] About 340 species, widely distributed. Type species: Scirpus 

 palustris L. 



Spikelets little, if at all, thicker than the culms; scales rigid; tall sedges. 



Achenes transversely ridged; culms nodose-septate. 1. E. interstinctu. 



Achenes copiously pitted : culms continuous. 2. E. ceUulosa. 



Spikelet thicker than the culm ; scales membranous ; low sedges. 



Upper sheath hyaline, scarious. 3. E. flaccida. 



Upper sheath truncate, oblique or 1-toothed. 



Perianth-bristles nearly white: achene 0.5 mm. long; 



culms nearly filiform. 4. E. atropurpurea. 



Perianth-bristles brown ; achene 1 mm. long ; culms slen- 

 der. 5. E. capitata. 



1. Eleocharis interstincta (Vahl) E, & S. Syst. 2: 149. 1817. 



Scirpus inter stinctus Vahl, Enum. 2: 251. 1806. 



Perennial by stout rootstocks; culms stout, terete, 4-10 dm. tall, nodose, 

 hollow. Sheaths oblique, the lower sometimes bearing short blades; spikelet 

 cylindric, terete, 2-4 cm. long, 4-5 mm. thick; scales coriaceous, obtuse, 

 faintly many-nerved, scarious-margined ; bristles about 6, retrorsely barbed, as 

 long as the achene or shorter; style 3-eleft rarely 2-eleft; achene obovola, 

 shining, brown, minutely many-striate and transversely ridged; tubercle conic, 

 acute. 



Marshes, Great Bahama, New Providence, Acklin's Island : eastern United 

 States ; Bermuda : Cuba to St. Thomas and Trinidad ; Jamaica ; tropical continental 

 America. Knotted Spike-rush. 



2. Eleocharis cellulosa Torr. Ann. Lye. N. Y. 3: 298. 1836. 



Perennial by long rootstocks; culms obscurely 3-angled below, terete above, 

 7 dm. tall or less, not nodose. Sheaths membranous, oblique; spikelet 1.5-3 

 cm. long, 2.5-4 mm. thick, cylindric, somewhat thicker than the culm; scales 

 coriaceous, obtuse, membranous-margined, many-striate; bristles 6 or 7, nearly 

 or quite smooth, about as long as the achene; style 3-cleft; achene broadly 

 obovoid, trigonous, striate, copiously pitted; tubercle deltoid, about one-half as 

 wide as the achene. 



Marshes, Abaco, Great Bahama, Andros, New Providence, Rose Island, Eleuth- 

 era, Crooked Island, Fortune Island, Great Emma, Inagua : southern United 

 States ; Bermuda ; Cuba ; Porto Rico ; Jamaica ; Yucatan. Round-stemmed Spike- 

 rush. 



* 3. Eleocharis flaccida (Rehb.) Urban, Symb. Ant. 2: 165. 1900. 



Scirpus flaccidus Rchb. ; Spreng. Tent. Suppl. 3. 1828. 



Eleocharis ochreata Nees, Linnaea 9: 294. 1834. 



Scirpus ochreatus Griseb. Fl. Br. W. I. 570. 1864. 



Heleocharis bahamensis Boeckl. Cyp. Nov. 2: 11 in part. 1890. 



Perennial by slender rootstocks; culms slender or filiform, 3-angled, 0.5-3 

 dm. long. Upper sheath white, hyaline, membranous ; spikelet oblong or ovoid, 

 3-6 mm. long, 2-2.5 mm. thick, much thicker than the culm; scales ellipticto 

 oblong-lanceolate, obtuse or the upper acute, thin, pale green with a faint 

 midvein; style 2-cleft; achene lenticular, obovate, smooth, 0.5 mm. long, 2-4 

 times as long as the conic, acute tubercle ; bristles 6 or 7, retrorsely barbed, as 

 long as the achene, or shorter, or none. 



Wet grounds, New Providence, Eleuthera : Southeastern United States : Cuba 

 to St. Thomas and Trinidad ; Jamaica ; tropical continental America ; Philippine 

 Islands. Pale Spike-rush. 



