BULLETIN OF THE 



UMPmiofAfflajiM 



No. 179 



Contribution from the Bureau of Plant Industry, Wm. A. Taylor, Chief, 

 April 2, 1915. 



(PROFESSIONAL PAPER.) 



NATIVE AMERICAN SPECIES OF PRUNUS.^ 



By W. F. Wight, 

 Botanist, Horticultural and Pomological Investigations. 



INTRODUCTION. 



The present study embraces only those species of the genus Prunus 

 which have an umbellate or corymbose inflorescence and which pro- 

 duce plumlike or cherrylike fruit, these being the ones principally 

 of interest, either from the standpomt of their fruit production or 

 their utilization as stocks in the propagation of other species. Indeed, 

 the American species belonging to the subgenera Padus, Laurocerasus, 

 and Emplectocladus seem sufiiciently distinct to warrant the recog- 

 nition of these groups as genera. If connecting species exist, they 

 are to be found among the Asiatic representatives of the genus, and 

 no satisfactory conclusions can be reached regarding generic limita- 

 tions without a careful study of the species in the Old World. 



DISTRIBUTION. 



The genus Prunus is widely distributed in America, being repre- 

 sented in some portion of every State by one or more species. One 

 species is found in northeastern Mexico, and one or more occur in 

 nearly all of the southern provinces of Canada. Eight species are 

 found within the limits of Texas, and it is probable that the greatest 

 abundance of individuals is in the region comprising Missouri, 

 eastern Kansas, Oklahoma, western Arkansas, northwestern Loui- 

 siana, and eastern and northern Texas. The species naturally grow 

 mainly in open situations, some of them scarcely at all with other 

 woody plants, and rarely under forest conditions. In some sections 

 of the country the clearing of the forests and the use of such areas 



' This manuscTipt was prcpare'l in 1911 wlilln Iho writer was associato'l wiUi l,lio Ollico of 'Paxonomic 

 uri'l Itancc Investigations. 



.NoTK.— This bulletin Is intcndcl for horticniltiirists in all parts of tlio United States, ospocially those 

 who arc stU'lylnK varieties or doing work in plant breeding. 



74240'— Bull. 179— l.l- 



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