Systematik und Pflanzengeographie. 53 



Flowers white, very small, leaves thin, light green, seeds (seen 

 from in front) gradually attenuated to the beak. E. alpinum. 

 Leaves quite small, nsually nearly entire. 



Stern ascending or ahnost creeping, öfter G-shaped, cespioste, leaves 

 relatively broad and sprending, uniformly distributed. 



E. anagallidifolium. 

 Stern erect not cespitose, leaves strict, the uppermost remote and 

 linear. E. Oregonense. 



Ü. Seeds papillately roughened under the microscope. 



a. Leaves linear to lanceolate , nearly entire , generally without con- 

 spicuous lateral veins. 



Leaves slightly revolute, sobols filiform, at length endins in large 

 turions, seeds large, elongated. 



Simple or nearly so , crisp. pubescent , leaves sessile, usually 

 obtuse. E. palustre. 



Mostly branched above, leaves more acute. 



Crisp. pubescent, leaves very narrow, petioled. E. lineare. 



Softly white glandulär, leaves lanceolate sessile. E. strictum. 



Leaves not revolute, sometimes involute in paniculatum. 



Innovation and seeds as in the last group. Hybrids of E. palustre. 

 Innovation various, never filiform. 



Rosuliforms, unbranched, not cespitose, leaves very blunt, crowded 

 below, seeds as the last group. E. Davurictim. 



Annuals, with broad obovoid seeds and* very deciduous coma. 

 Dichotomous. glabrous or grandular, seeds large. 



E. paniculatum. 

 Simple or panicled, crisp. pubescent, seeds halr as large. 



E. ininutum. 

 Turioniferous, coma more persistent. Small plants. 

 Branched, leaves small, acute, petioled, coma reddish. 



E. leptocarpum. 

 Simple or sometimes branched below in the first and cespitose 

 in the last, leaves sessile or susbessile, seeds broader with 

 pale coma. 



Tomentose throughout and somewhat pilose. 



E. ursinum var. subfalcatum. 

 No long hairs , glabrous below or crisp. pubescent in 

 lines only. 



Not cespitose, pubescence scanty, leaves obtuse drying 



light, the upper nearly linear. E. delicatum var. tenue. 



Often cespitose, quite glandulär obove, even as to the cub- 



acute leaves which dry dark. E. saximontanum. 



Soboliferous and cespitose, glaucous, seeds broad. E. glaberrimum. 



Cespitose by stolons , very slender-stemmed, not pilose, occasi 



onally glaucous in the first, seed elongated. 



Leaves erect, narrow, keeled below. 



E. Oregonense var. gracillimum, 



Leaves more spreading, broader, not keeled. E. clavatum. 



1>) Leaves lanceolate to ovate, evidently toothed, reiny (or often subentire 

 and less reiny in the last three) not revolute. 



Dichotomous, aunual, pubescence not crisp, leaves slender — stalked, 

 acute, seeds very broad and obtuse. E. paniculatum. 



Simple or nearly so, apparently annual, pubescence crisp . . . dwarf 

 form referred to E. adenocaulon. 



Rosuliferous, not glaucous, laeves with at least short winged petioles. 

 Flowers large for the group, the violes petals 6 to 10 mm long. 

 Pacific species. 



Stem subtomentose, little branched, leaves elliptical, obtuse, flowers 

 protruding beyond the terminal leaves. E. Watsoni. 



Glabrate below, more branched, leaves ovate-lanceolate, the upper 

 acute. 



