490 Rydberg: Notes on Rosaceae 



retained up to 1906, when Dr. Greene segregated from it Acomasty- 

 lis and Erythrocoma. In my opinion the former was rightly 

 taken out, as it differs from Sieversia by the same character of 

 the fruit that separates Anemone from Pulsatilla. Erythrocoma 

 on the other hand I can not regard as distinct generically from 

 Sieversia. Its species differ from the type of Sieversia only in 

 the erect instead of spreading petals and a better developed 

 hypanthium. If Erythrocoma should be kept distinct, Geum rivale 

 should be taken out of Geum, as it differs by just the same char- 

 acters, and still that species frequently hybridizes with the other 

 species. Dr. Greene made the following statements which are 

 not exactly true: " Sieversia was founded on a Siberian under- 

 shrub, low and slender, with almost rotate calyx and corolla, the 

 former nearly chorisepalous, and its mature styles are long, filiform, 

 plumose to the very apex." There are apparently three species 

 which have gone under the name Sieversia anemonoides, of which 

 one can be called an undershrub, the other two having the habit of 

 Dryas octopetala, being strongly cespitose with the branches more 

 or less covered by soil and moss. I think the type of Sieversia 

 was one of these. The difference between this cespitose stem and 

 the branching rootstock of Erythrocoma is indeed very small. 

 The styles of Sieversia anemonoides Willd., or S. pentapetala (L.) 

 Greene, are not plumose to the apex, for the upper part is naked, 

 soft, withering, as it is in Erythrocoma, the only difference being 

 that it is very short, scarcely 2 mm. long. This naked portion 

 of the style is found not only in the type of Sieversia and in S. 

 ciliata and its relatives, but also in the S. montana group, to which 

 5 1 . radicata, S. Peckii and S. calthifolia belong. The naked portion 

 in most is rather persistent, although usually withering in age, 

 but in some species or even individuals it breaks off. It is how- 

 ever never articulated to the lower portion of the style as in Geum, 

 where the upper portion, which is usually hairy, falls off very 

 early. C. P. Smith* describes the style of Erythrocoma ciliata as 

 follows: "Style hooked, or articulated [italics mine], the terminal 

 portion often deciduous." I have seen it somewhat bent or even 

 occasionally hooked, but never with a proper articulation. The 

 soft upper naked portion, after it has withered, often falls off at 



* Muhlenbergia 8: 7. 1912. 



