PLANTS FROM NORTH DAKOTA 287 
NEW PLANTS FROM NORTH DAKOTA.—IX. 
BY J. LUNELL. 
Rosa dulcissima sp. nov. 
Caudex spinis rectis, tenuibus, fragilibus, infra stipulas 
maioribus armatus. Stipulae per marginem totam vel ferme 
totam glanduloso-serratae, superne glabratae, subtus pubescentes. 
Rachis folii tomentulosa, saepe spinulosa. Foliola 5—9, in surculis 
usque 11, late ovata vel obovata, basi cuneata, apice obtuso 
vel acuto, simpliciter vel duplo serrata, 3-6 cm. longa, 2—4 cm. 
lata, conspicue petiolulata superne glabrata, subtus glauca et 
indumento magis minusve evanescente vestita. Flores 4-6 cm: 
lati, corymbosi. Receptaculum atratum, interdum _ setosum. 
Sepala paralleli-nervia, vehementer glanduloso-hispida, interne et 
marginaliter albido-lanata, apicibus longis glabratis, exteriora 
pinnis mediano-nervatis glabratis insigniter pinnatifida. Frug¢tus 
globosus vel pomiformis, 12-15 mm. latus. 
Stem armed with straight, narrow, weak prickles which are 
Jargest beneath the stipules. Stipules glandular-serrate for their 
whole length or nearly so, glabrate above, pubescent beneath. 
Leaf-rachis tomentulose, often with prickles. Leaflets 5-9, in 
young shoots sometimes 11, broady ovate or obovate, with cuneate 
base and obtuse or acute apex, simply or doubly serrate, 3-6 cm. 
long, 2-4 cm. wide, prominently petiolulate, glabrate on the 
upper side, glaucous with a more or less evanescent indument 
beneath. Flowers 4-6 cm. wide, corymbose. Receptacle dark, 
with occasional setae. Sepals parallel-nerved, strongly glandular- 
hispid, white-woolly within and on the margins, the outer notably 
pinnatifid with glabrate, median-nerved pinnae and long, glabrate 
tips. Fruit globose or apple-shaped, 12-15 nm. broad. 
The features specifically distinguishing this rose from my R. 
gratiosa are its almost constantly corymbose flowers and its strongly 
pinnatifid outer sepals. The latter has flowers either corymbose 
or solitary, and sepals essentially and constantly entire, only 
exceptionally bearing a minute lobe, with often fusiform heps. 
Collected on or just inside of the external margin of the 
woodland surrounding Pleasant Lake, Benson County, on July 
4 and September 2, 1912, by the writer, 
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