Rydberg: Notes ox Rosaceae 



161 



3. Rosa rubiginosa L. 



The European sweet brier, often cultivated, has established 

 itself at several places in Oregon and Washington. It is very 

 variable and the naturalized specimens show also much variation. 

 One of chese many forms, which is rather more glandular than 

 usual, was mistaken for a rative species and published by Dr. 

 E. L. Greene as new, under the name R. Walpoleana. The 

 author placed it in the Gymxocarpae, a group to which it has no 

 relation. 



4. Rosa micraxtha Borrer 



See Bull. Torrey Club 47: 49. 1920. This species also is 

 naturalized in Oregon and Washington. 



III. CINNAMOMIAE 



Infra-stipular prickles not present; branches unarmed or 

 bristly, not prickly. 

 Stem densely bristly even in age; flowers solitary. 



Hypanthium decidedly pear-shaped or ellipsoid, acute 

 at the base, with a distinct neck at the top. 

 Sepals rarely more than i cm. long; bark yellowish 



green. 

 Sepals 2-3 cm. long; bark brown. 



Leaflets obovate, sparingly hairy beneath. 

 Leaflets elliptic, densely pubescent beneath. 

 Hypanthium subglobose, almost without a neck. 

 Stem unarmed or when young covered with more or less 

 deciduous bristles; flowers corymbose. 

 Fruit ellipsoid; leaflets serrate. 

 Fruit subglobose; leaflets crenate. 

 Infra-stipular prickles present. 



Flowers mostly solitary; petals usually 2.5 cm. long or 

 more (except in No. 11); hypanthium in fruit 12-20 

 mm. thick. 

 Prickles straight or nearly so. 

 Hypanthium densely prickly. 

 Hypanthium not prickly or rarely slightly so. 



Leaflets more or less double-toothed, more or 

 less glandular-granuliferous beneath; stip- 

 ules and rachis glandular. 

 Pedicels and calyx densely bristly but hypan- 

 thium glabrous; leaflets oval, rarely 2 cm. 

 long; prickles weak; petals 15 mm. long. 

 Pedicels and calyx not bristly, sometimes 

 slightly glandular-hispid. 



10. R. MacDougalii. 



11. R. yainacensis. 



