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, i. 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,t 
makes the following remark: ‘‘The red-flowered form of this species 
is referred by Howell to’ S. officinalis L. The white-flowered 
ordinary form was referred to S. 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. Mensziesii Rydb., described 
in the North American Flora. Howell’s S. 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 S. microcephala Presl. 
POTERIDIUM 
I believe that the genus Poteridium Spach should be reéstab- 
lished for the annual species of Sanguisorba with brush-like stigmas. 
The first species of this genus was originally described as Potertum 
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 
2D. LI Be 334. 
t Contr. U. S. Nat. a 1X7. 336. 1006. 
