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Distribution. Massachusetts to Florida, west to Manitoba and 

 south to New Mexico. Found throughout Indiana. While it has a 

 general distribution, it is not generally distributed through the forests, 

 but is local in colonies in low grounds along streams or in low places in 

 the forest. In the southern counties it is found on the ridges and com- 

 monly about the basins of sink-holes. Large single trees may be found 

 but they are usually surrounded by many smaller ones which are root 

 shoots. From this habit of the tree to produce root shoots large colonies 

 are formed which has given rise to the term "plum thickets." 



Remarks. The wood of this tree is of no economic importance, but 

 the species from a horticultural standpoint is one of the most important 

 of all of the plums. Many named varieties belong to this species. 



It should be noted that all species of plums are quite variable, and 

 one must not be surprised to find specimens that will not come entirely 

 within the descriptions. 



2. Prunus americana var. lanataSudworth. WOOLLY-LEAF PLUM. 

 Plate 100. Small trees with the characteristic wild plum tree bark, except 

 on age it becomes more furrowed ; twigs generally puberulent or sometimes 

 smooth; leaves obovate, oblong-obovate, or sometimes somewhat ovate, 

 generally about 6-10 cm. long, and 4-6 cm. wide, rounded at the base, 

 acute or short acuminate at the apex, margins sharply serrate, or 

 doubly serrate, upper surface covered with short appressed hairs, lower 

 surface permanently pubescent with longer hairs; petioles more or less 

 pubescent and often bearing one or more glands; flowers appear in 

 April or May in umbels of 2-4, upper part of calyx, and its lobes pube- 

 scent both inside and out, the lobes more or less cut-toothed and 

 bearing inconspicuous glands; fruit ripening in September, globose, 

 reddish with a bluish bloom; stone nearly orbicular and turgid. 



Distribution. Indiana west to Indian Territory and south to the 

 Gulf. The range of this variety has not been well understood, and it is 

 believed that forms of this variety in the northern part of its range 

 have been included in the preceding species. It is certain that in our 

 area the two forms are separated with difficulty; especially is this 

 true of certain individuals. Specimens at hand show it to occui in 

 Floyd, Clark, Bartholomew, Martin, Warren, Vermillion, Gibson, 

 Warrick, and Perry Counties. 



Remarks. This form intergrades with the preceding to such an extent 

 that there is little difference between the extremes of the two forms. 



3. Prunus nigra Aiton. CANADA PLUM. Plate 101. Small 

 trees with the characteristic bark of the genus; twigs smooth; leaves 

 obovate or oval, 5-11 cm. long and 3-6 cm. wide, rounded or somewhat 



