CLASS XII. ORDER I. 205 



It differs from P. Virgin iana, and P. Serotina of Muhlenberg 

 and Willdenow, in its obovate and sharply serrated leaves, small 

 size, early flowering and red fruit. 



Prunus borealis. Pursh. Northern Wild Cherry/. 



Corymbs with elongated pedicels ; leaves oval- 

 oblong, acuminate, slightl)^ eroded, membranous, 

 smooth ; fruit subovate. 

 Syn. Cerasus borealis. Mr. 



A small tree, with very thin, delicate leaves, and small, red, 

 astringent fruit. — On Blue hills, Milton. Common in Maine, 

 where it succeeds to pine forests, which have been cut down. — 

 May. 



Prunus depressa. Pursh. Sand Cherry. 



Umbels sessile, aggregate, few flowered ; branches 

 angular, prostrate ; leaves wedge-lanceolate, slightly 

 serrate, smooth, glaucotis underneath ; fruit ovate. 

 Syn. Cerastjs pumila. Mx. 



A small, trailing shrub, spreading its branches close to the 

 ground. — On the shores of Lake Champlain. — May. 



* Prunus littoralis. Beach Plum. 



P. iimbelUs conglomeratis, paticijloris : pedvncuUs 

 calycibusqve svbptibescentibus ; foliis ovalibus ocuiis, 

 sei'ralis, venis stiblns pubescentibus. 



Umbels crowded, few flowered ; peduncles and ca- 

 lyxes somewhat pubescent; leaves oval, acute, ser- 

 rate, the veins pubescent beneath. 



Syn. Prunus spHvErocarpa. Mx.? ncc Willd. 

 Prunus pubescens. Ph. ? 

 A shrub with stout, straggling branches. Leaves scattered, 

 crowded, oval or obovate, acute, single and doubly serrate, 

 smooth or rugose above, slightly pubescent or tomentose beneath. 

 Petioles short, pubescent, and biglandular. The flowers appear 

 before the leaves on the sides near the extremities of the last 

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