322 Rydberg: Notes on Rosaceae 



he changed it to A. achilleaefolia Remy.* Remy's species was 

 based on Dombey's plant from Peru, he overlooking the fact that 

 this plant belonged to the original A. pinnata R. &. P. He, there- 

 fore, originally described the same plant under the same name, 

 and consequently the second synonym was superfluous. 



SANGUISORBA 



In the North American Flora, the genus Sanguisorba was taken 

 in its original narrower sense, *. e., the perennial species with only 

 2-4 stamens, and 1 pistil with muricate papillose stigmas. Of this 

 genus, four native North American and one introduced species, 

 S. officinalis L., were recognized. 



Sanguisorba canadensis L. is limited to the northeastern part 

 of this continent. The plants referred to it from the northwest 

 belong to the following two species. 



Sanguisorba sitchensis C. A. Meyer [S. latifolia (Hook.) 

 Coville] has white flowers. Piper in his Flora of Washington,! 

 makes the following remark: "The red-flowered form of this species 

 is referred by Howell to 5. officinalis L. The white-flowered 

 ordinary form was referred to 5. media L. in Hooker's Flora." 

 This statement is not correct. Hooker's S. media is described as 

 having red flowers and is the same as S. Menziesii Rydb., described 

 in the North American Flora. Howell's 5. officinalis has, as 

 stated, red flowers, but the filaments are but slightly exserted and 

 filiform, not twice as long as the sepals nor dilated. It is the 

 same as 5. microcephalia Presl. 



POTERIDIUM 



I believe that the genus Poteridium Spach should be reestab- 

 lished for the annual species of Sanguisorba with brush-like stigmas. 

 The first species of this genus was originally described as Poterium 

 annuum Nutt. in Hooker's Flora Boreali-Americana. Hooker 

 adopted Nuttall's manuscript name, which the author had applied 

 to the species growing in Arkansas and neighboring states, but the 

 specimens treated in that flora belong to the Pacific coast species. 

 Hooker's Poterium annuum is, therefore, a composite. The 



* L. c. III. 8: 224. 1847. 



t Contr. U. S. Nat. Herb, n: 336. 1906. 



