580 



ROSAOEAE 



Primus 



local to infrequent except on the slopes of the dunes facing Lake Michigan 

 and on the low dunes near Lake Michigan west of Gary where it is fre- 

 quent to common. In the interdunal flats a short distance from the lake 

 large colonies may be found. Away from the lake it grows in moist, black, 

 sandy soil and is usually about 3 feet high and erect or slightly decumbent 

 near the base, but along the lake it is always decumbent at the base and 

 sometimes reaches a length of 5-8 feet. I have had this species in cultiva- 

 tion from seed from the shore of Lake Michigan and the plants grow 

 rapidly and are erect until they reach a height of 5-8 feet when they either 

 become decumbent or break off near the ground. 



Prunus cuneata and Primus susquehanae are named forms of Prunus 

 pumila which I do not regard as of taxonomic value. For a discussion of 

 these species see excluded species nos. 381 and 383, on p. 1064. 



Maine to Minn., southw. to N. Y. and Ind. 



4. Prunus angustifolia Marsh. Chickasaw Plum. Map 1185. I feel 

 positive that this species was never native to Indiana and I think that 

 our few reports can safely be referred to naturalized plants. I have seen 

 it persist in a fallow field in the Clark County State Forest after cultivation 

 and spread over an area, as nearly as I can recall, of about half an acre 

 in 30 years. 1 have seen it frequently in large colonies in fallow fields about 

 former habitations. In no instance have I seen it in a place where I would 

 regard it as native and it should be referred to the introduced species. 



Sargent says: "Probably native in cent. Tex. and Okla." Now widely 

 naturalized from Del. to Ky., southw. to the Gulf. 



5. Prunus nigra Ait. Canada Plum. Map 1186. Very local in the 

 northern half of the state where it is found in wet woodland. All of the 

 specimens I have seen in the wild were small, although one which I trans- 

 planted grew to a diameter of 7 inches at breast height when it was killed 

 by borers. Its flowers are large, somewhat pinkish, and profuse; they 



