496 MINNESOTA BOTANICAL STUDIES. 



ing over the wet ground. High altitudes, Sierra and Trinity 

 Mts., California to Colorado and northward. 

 Var. Populago n. var. 



R. Populago GREENE, Erythea, 3 : 19. January, 1895. 

 R. Cusickii JONES, Proc. Calif. Acad. Sci., Ser. 2, 5 : 615. 



October; 1895. 



Like the type, but with radical leaves ovate, cordate ; mar- 

 gins slightly wavy. Southwestern Oregon, Idaho. 



83. R. Lemmoni GRAY, Proc. Am. Acad. 10 : 68. 1874. 



Stems scapose, tufted, 5 to 10 inches high : plant villous- 

 pubescent on lower parts : leaves rather thick, lanceolate, en- 

 tire : flowers i or 2 on a stem ; petals about three lines long, 

 obovate to oblong : akenes turgid, villous-pubescent, borne in 

 an oval head. Rare. Truckee and east part of Sierras, Cali- 

 fornia. 



84. R. oblongifolius ELL. Sketch 2 : 58. 1824. 



R. Flamniula MICHX. Fl. i : 221. 1803. Not Linn. 

 R. Flammula var. laxicanlis TORR. & GRAY, Fl. i : 16, 



1838. 



R. pusillus var. oblongifolius TORR. & GRAY, 1. c. 17. 

 R. laxicanlis DARBY, Bot. S. St. 204. 1855. 



Annual ; about i to 2 feet high, erect or ascending, rarely 

 rooting at the lower nodes, branched above, many-flowered : 

 leaves shaped nearly as in R. -pusillus^ or sometimes broader : 

 petals 5, yellow, longer than the sepals ; stamens many : akenes 

 few, often globular or slightly flattened, smooth or minutely 

 punctate ; style deciduous : head of fruit globose. April to Sep- 

 tember. Wet grounds. Florida to southern Virginia, west to 

 southern Missouri and Texas. 



85. R. hydrocharoides GRAY, Mem. Am. Acad. 5: 306. 



1855- 



Stems ascending, 5 to 10 inches high, rooting at the lower 

 nodes, with creeping, fistulous branches at the base : leaves 

 mostly long-petioled, entirely or nearly so, usually less than i 

 inch long, rather succulent ; basal leaves round-cordate to oval, 

 blending into the form of the upper ones which are obovate to 

 spatulate : petals 5 or more, 2 to 3 lines long ; sepals much 

 shorter : akenes small ; beak narrow, short : head of fruit small, 

 globose. In standing water and wet soil. Southwestern Ari- 



