232 



PENNYP ACKER— ON THE BEACH PLUM 



I. Introduction and History 



1. Introduction 

 This subject was first suggested to me by Dr. J. M. Macfarlane, he 

 having pointed out to me the marked variations which he had observed 

 in the fruits of the plants which are produced at various places along the 

 Atlantic coast from Cape Cod, Mass., to Cape May Point, N. J., and 

 upon which he later pubhshed a paper entitled, "The Beach Plum, 

 Viewed from Botanical and Economic Aspects" (18, p. 216). In that 

 paper, he dwelt entirely on the variations as exhibited by the fruits, and 

 also suggested various evolutionary lines by which these varieties may 

 have evolved. He suggested to me, in view of the facts just set forth, the 

 possibility of finding variations in other aspects of the plants, which I 

 might correlate with the fruit variations. It was with this idea in mind 

 that I undertook the present work. After extensive research, I have 

 found certain varietal differences, which seem of sufficient importance 

 to warrant the division of Prunus maritima (Marsh) iato the following 

 varieties: — 



1. Prunus maritima YQX. caerulea-magna. 



2. " " var. caerulea parva. 



3. " " var. praecox. 



4. " " var. pu -purea magna. 



5. " " var. purpurea parva. 



6. " " var. rubra magna. 



7. " " var. rubra parva. 



8. " " var. lutea magna. 



9. " " var. lutea parva. 



2. Review of Literature 



The history of the work which has been done upon this plant deals 

 almost entirely with the taxonomic or systematic phase of the species. 

 At first it was described by difi'erent botanists under numerous synonyms, 

 but the similarity of these being later discovered it is now known as 

 Prunus maritima. 



It was first described by Marshall (19, p. 112) in 1785. He called 

 it Prunus maritima, "The Seaside Plumb," and the description, though 

 brief, was probably sufficient for that day. By way of general interest 

 and comparison, it is now quoted: "This grows naturally toward the 

 sea coast, rising to the height of eight to ten feet, often leaning and 

 spreading into many branches. The leaves are oblong, rather smaller 



