492 PROCEEDINGS OF THE AMERICAN ACADEaiY. 



Synopsis of Species.^ 



* Bristles overtopping tlie body of the achene. 



-t- Tubercle nearly or quite as broad as the achene. 



•M- Heads from globose-ovate to ovate-oblong : scales brown, obtuse. 



E. OBTUSA, Schultes. — Figs. 1 to 7. — Culms generally many, compar- 

 atively stout, erect or ascending, 1 to 5 dm. high : heads globose-ovoid to 

 ovate-oblong, obtuse, densely-flowered, 3 to 13 mm. long, 3 to 5 mm. 

 broad : scales obovate, obovate-oblong, or suborbicular, ascending, close- 

 appressed, dull brown or rarely chestnut-brown with pale scarious blunt 

 or rounded margins and comparatively pale broad midribs : achenes mostly 

 cuneate-obovate ; tubercle depressed, about a third as high as the body 

 of the achene. — Mant. ii. 89; Torr. Ann. Lye. Nat. Hist. N. Y. iii. 

 302; Gray, Man. 522; &c. E. (^Heleocharis) ovata, Bockeler, Linna^a, 

 xxxvi. 462, in part; C. B. Clarke, Jour. Bot. xxv. 2G8, in part; Wats. & 

 Coulter in Gray, Man. ed. G, 574 ; Britton, Jour. N. Y. Microsc. Soc. 

 V. 102; Britton & Brown, 111. Fl. i. 251, f. 584 (as to habital sketch) ; 

 not R. Br. Scirpus obtusus, Willd. Enum. Hort. Berol. i. 70. S. cap- 

 itatus, Walt. Fl. Car. 70 ; Pursh, Fl. i. 55 ; Ell. Sk. i. 77 ; Torr. Fl. 

 N. & Midd. U. S. 45 ; and many other authors ; not Willd. S. ovatus, 

 Muhl. Cat. 6; Pursh, Fl. i. 54; not Roth. S. elegantulus, Steud. Cyp. 

 317. — A common plant in muddy or wet places nearly throughout eastern 

 North America, growing from Whycocozmah, Cape Breton (Alacoim), 

 Kent County, New Brunswick {Fowler), Piscataquis County, Maine 

 {Fernald, no. 251), Ste. Clotilde, Quebec {St. Cyr), and Ottawa, 

 Ontario {Macoun), to Minnesota ( Woods, Sandberg, no. 6G9, Taylor), 

 Iowa {Butler, Fink), and Kansas {Norton, no. 545) southward to the 

 Gulf of Mexico. Reappearing in the northwestern United States and 

 British Columbia: Green River Hot Springs, Washington {Piper, no. 

 G280) ; Clarke Co., Washington {Suksdorf, no. 2328) ; Pitt River, 

 British Columbia {Hill). Some northern specimens not otherwise dis- 

 tinguishable from typical E. obtusa have castaneous scales. 



Var. jejuna. — Figs. 13, 14. — Culms capillary, suberect or gen- 

 erally decumbent or spreading, 1 (rarely 2) dm. or less high : heads 

 smaller, fewer-flowered, 2 to 5 mm. long ; scales more spreading : achene 



1 The number and character of the stamens have sometimes been given promi- 

 nence in distinguisliing species of Eleocharis. When the achenes are well matured, 

 however, the stamens are too often shrivelled or entirely gone, so that the differ- 

 ences found in them are hardly satisfactory criteria for determining species. 



