100 



Rydberg: Notes ox Rosaceae 



Stem climbing, with scattered prickles, rarely with 

 intermixed bristles; sepals more or less lobed; foliage 

 glandular-punctate, sweet-scented. 

 Stem not climbing, at least the young shoots bristly; 

 prickles infra-stipular or lacking; sepals entire or the 

 outer sometimes with one or two lobes; foliage not 

 very sweet-scented. 

 Pistils few; styles deciduous with the upper part of the 

 hypanthium, which falls off like a ring. 



II. Caninae. 



III. ClNNAMOMEAE. 



IV. Gymnocarpae. 



I. SYNSTYLAE 



Stipules pectinately lobed and glandular-ciliate; corymb 



many-flowered. 

 Stipules merely serrate; corymb one- to few-flowered. 



1. R. midli 'flora. 



2. R. arvensis. 



I. Rosa multiflora Thunb. 



See my notes in the preceding paper of this series.* The 



species has been reported as a ballast plant at one station in 



Washington. 



2. Rosa arvensis Huds. 

 I 



The following specimens were sent to me by J. C. Nelson, 

 principal of the high school at Salem, Oregon, for determination. 

 In the accompanying letter Mr. Nelson wrote among other things: 

 "He [the collector] reports this form as common in the vicinity of 

 Vancouver [Washington], apparently fully spontaneous. The 

 flowers were always single, and the petals of a wonderful shade of 

 pearly white." The specimens apparently belong to the so-called 

 Ayrshire Rose, which is by some regarded as a form of R. arvensis, 

 by others as a hybrid of the same. The leaflets are larger and 

 more pointed and the sepals more inclined to be lobed than in the 

 wild English form of that species. 



Washington: Vancouver, R. V. Bradshaw 105 j. 



II. CANINAE 



Leaflets suborbicular or broadly oval, mostly rounded at the 

 apex; hypanthium in fruit obovoid or broadly ellipsoid, 

 abruptly contracted at the apex; sepals tardily deciduous 

 or persistent. 



Leaflets ovate or oval, acute or short-acuminate; hypanthium 

 in fruit narrowly ellipsoid, tapering at both ends; sepals 

 early deciduous; styles glabrous or nearly so. 



3. R. rul 



4. R. micrantha. 



* Bull. Torrey Club 47: 47- 1920. 



