2 26 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN. 



Rosa gymnocarpa Xutt ; Torr. & Gray, Fl. N. Am. i : 461 [Wats. 



Proc. Am. Acad. 20: 350; Man. R. M. 88; Bot. Cal. i: 187]. 



Found only in the western part of Montana. 



Montana: Columbia Falls, 1892, 7?. 6\ Williams: Bitter Root 

 River, 1880, Waisoii ; Flathead 'Ldi'k.Q:, Sargent ; Flathead River, 

 1883, Canby, loj. 



DRUPACEAE. 



Prunus Americana Marsh. Arb. Am. iii [Man. R. M. 76: 111. Fl. 



2: 247]. 



Along streams in the eastern part of the state, reaching an alti- 

 tude of 1500 m. 



* Prunus corymbulosa. 



A small shrub, 1-2 m. high; bark dark brown, shining, more or 

 less dotted with lenticels ; leaves glabrous and shining, 4-6 cm. long, 

 ovate-lanceolate, acute or acuminate, finely crenate with mucronu- 

 late teeth ; flowers appearing with the leaves, in small 3-6-flowered 

 corymbs, which are often subtended by one or two small leaves; 

 sepals broadlv obovate or rounded, more or less wavy and erose ; 

 petals broadly obovate, about 4 mm. long, more or less wavy-mar- 

 gined. 



In foliage it is strikingly like P. Pcnnsylvanica, but differs in the 

 inflorescence, which is more like that of P. mollis. All specimens 

 seen were small shrubs, scarcely over i m. high ; only one was 

 found m bloom. The leaves generally have a pair of small glands 

 at the base of the blade. Specimens of this species, when not in 

 flower or fruit, might be mistaken for the dwarf Rocky Mountain form 

 of P. Pcnnsxlvaiiica. 



Montana : Bridger Mountains, June 18, 1897, Rydhcrg- ci- Besscy, 

 443 J : Little Rocky Mountains, Dr. V. Hazard. 



Prunus demissa (Nutt.) Walp. Rep. 2 :io [Man. R. jNI. 77 ; 111. Fl. 



2 : 253 ; Bot. Cal. i : 167] ; Ccrasus demissa Nutt. ; Torr. & Gra}-, 



Fl. N. Am. I : 44. 



Rather common in canons and valleys, at an altitude of 1000- 

 2500 m. 



Montana: Madison Co., 1888, F. Tweedy, pj : Spanish Basin, 

 June 26, 1897, R\'dbe?'g d- Bessey, 4436; Emigrant Gulch, Aug. 

 23, 4433 ; Bridger Mts., June 12 and 18, 4433 and 4434; Great 

 Falls, 1892, R. S. Williams, 3g2; Helena, 1882, Kchey ; Madison 



