122 EEYTHEA. 



selves are smooth in R. eremogenes, but distinctly rugulose in 

 H. sceleratus; and the mode of branching is strikingly 

 different in the two. 



Though first detected by Nuttall on the plains of the 

 Platte, the most luxuriant specimens seen by me are from the 

 region of the muddy lakes that lie along the northwestern 

 border of the Great Basin in northeastern California and ad- 

 jacent Oregon. Smaller specimens, with leaves more finely 

 divided, were collected beyond the British boundary, on 

 Milk Kiver Ridge, by Mr. Macoun, in 1895 (n. 10036). I 

 have often observed it, and collected it myself along the 

 Humboldt River in Nevada, and along the Platte in Colorado. 

 All doubts about its validity as a species have vanished upon 

 seeing the real M. sceleratus as naturalized in Maryland, etc. 



M. eremogenes does not cross either the Sierra Nevada or 

 the Cascades to the more immediate Pacific Coast, where in 

 the vicinity of the seaports R. sceleraius may confidently be 

 expected as an immigrant. This was indeed collected once, 

 if I mistake not, at San Francisco, by Dr. Kellogg; but is not 

 yet known as established there. 



Ranunculus microlonchus. Perennial, the rather large 

 cluster of fleshy-fibrous roots supporting a tuft of erect lan- 

 ceolate leaves and a single slender tortuous, often partly 

 reclining leafy and few-flowered stem: leaves all entire, acute 

 at both ends, the radical 1 or 2 inches long, on slender peti- 

 oles as long, narrowly lanceolate, nearly glabrous above, but 

 rather densely appressed-pubescent beneath; cauline few, 

 relatively somewhat broader, with short petioles or subsessile; 

 flowers one or several, yellow, 4 lines broad; sepals spread- 

 ing; petals 5 to 8, obovate, obtuse: achenes few, in a 

 depressed-globose head, obliquely obovoid, slightly narrowed 

 at base, tipped with a short stout blunt style, moderately 

 compressed, marginless, smooth and glabrous. 



Collected by the writer in northern Idaho, August, 1889; 

 long withheld from publication in expectation of finding 

 traces of it in collections made by others in that region; 

 though it was detected by me in only a single locality. It is. 



