128 Muhlenbergia, Volume 5 



more it about held its own, when it began to rapidly diminish, 

 and is now no longer to be found. A few plants have appeared 

 sporadically at two other points, but have not reappeared in the 

 second season. No effort was made to eradicate either of these 

 plants, nor was there a change in the condition of the places in 

 which they grew. It simply appeared that, triumphant as they 

 have proved elsewhere, they here found themselves unsufficiently 

 adapted to the environment to succeed in the struggle for ex- 

 istence. 



San Bernardino, California 



CERTAIN CALIFORNIAN THALICTRA 

 By Edward L. Greene 



A subject of some earlier and much recent study on my 

 part has been that Thalictrum aggregate which began to figure 

 as a published species thirty years since under the name T. poly- 

 carpum (S. Wats. Proc. Am. Acad. 14: cS8. 1S79). The orig- 

 inal description is loose enough to cover a rather wide diversity 

 of species, and accordingly within the thirty years that have 

 passed a number of things notably different among themselves 

 have been referred to it; this partly because of the insufficiency 

 of Mr. Watson's diagnosis. 



In 1892 {Flora Francis cana^ 309) I was able, partly through 

 what Mr. Watson had never attained to, a field knowledge of 

 these plants, to effect a better definition and delimitation of the 

 species, one element of it, as it then existed in herbaria, appear- 

 ing as new, under the name T. caesium. More lately, having 

 surveyed a very great amount of dried material labeled T. poly- 

 carpu))i y I perceive that at this date further segregation is neces- 

 sary. It is also now apparent that the name T. polycarpu))i is 

 untenable. It had been chosen to designate an Old World mem- 

 ber of the genus twenty years before Mr. Watson attempted to 

 employ it. Since, then, the Watsonian type must be named 

 anew, I shall take this occasion to give it a fuller description. 



