NATIVE AMERICAN SPECIES OF PRUNUS. 



61 



ward to southwestern North Carolina and is said to reach its greatest 

 size in this region. 



The fruit of this species is not edible, but the tree is sometimes 

 used as a stock on which to bud the sour cherry (Prunus cerasus) and 

 in northern regions is the only stock on which that fruit has as yet 

 been successfully grown. A. S. Fuller (25, p. 184) notes as early as 

 1867 that the wood of this species and that of the cherry unite very 

 readily. 



Pruntjs Pennsylvanica Corymbulosa (Rydb.) W. F. Wight. 



Prunus corymbulosa Rydb., 190O, Cat. Fl. Mont., p. 226. 



Cerasus trichopetala Greene, 1905, in Proc. Biol. Soc. Wash., v. 18, p. 60. 



Prumis trichopetala Blankinship, 1905, in Mont. Agr. Coll. Sci. Studies, Bot., v. 1, 



No. 2, p. 70. 

 Prunus pennsylvanica saximontana Rehder, 1908, in Mitt. Deut. Dendrol. Gesell., 



No. 17, p. 160. 



Fig. 4.— Outline map of the United States, showing the distribution of native American species of 

 Prunus: Pcnruvjlvanica, cmarginata, pumiln, cuncata, and besscyi. 



Leaves ovate to ovate-lanceolate or sometimes oblong-bval (PI. VI, 

 fig. 2), narrowed toward the base, acute at the apex. Flowers 12 to 

 1 8 mm. broad, in sessile or sometimes pedunculate clusters of three 

 to six. Stone slightly ovoid, about 6 mm. long. 



The subspecies forms a small shrub, 3 to feet high, differing from 

 the species in its slirubby character and in the mature leaves being 

 broader in proportion to their length, and in the stone being slightly 

 ovoid instead of round-oval. 



Pninus pennsylvanica eaximontana was described from Colorado, 

 Wyoming, and the Black Hills region of South Dakota and was dis- 

 tinguisherl from tlie type of P. perm8ylva/nica corymbulosa by its sessile 



