30 MIDDLESEX FLORA. 



S. subvillosa, L. 

 Westford, near woollen-mills (Dr. 0. W. Swan). Adv. from Bu. 

 " Pod smooth, the interior ribs entire, the exterior bearing 6-8 stiff 

 spines, somewhat hooked at the apex." Koch, Syn. Fl. Germ. 



ROSACE/^. ROSE FAMILY. 



Prtxntjs, Toum. 



P. Americana, Marsh. Wild Yellow or Red Plum. 

 Concord (Minot Pratt) ; Medtord (L. L. Dame) ; Cambridge (fide 

 specimen in Gray Herb.); E. Lexington (C. W. Wellington). 

 Occasional ; fruit mostly dropping before maturity, or developing 

 into monstrosities. May. 



P. maritima, Wang. Beach Plum. 

 Chelmsford, Tyngsboro and Tewksbury (Dr. C. W. Swan) ; Wil- 

 mington (L. L. Dame). Kare. May. Possibly introduced from 

 the sea-coast. 



P. SPINOSA, L., var. insititia, Gray. Bullace Plum. 

 Found " in the woods near Mt. Auburn," by Oakes, whose speci- 

 men is in the Gray Herb.; reported growing "on the banks of the 

 Charles," in Emerson's Trees and Shrubs, 1846 ; and observed in 

 1885 by C. F. Batchelder, in the same locality, " scattered along at 

 Intervals for some distance." May. Nat. from Eu. 



P. pumila, L. Dwarf Cheret. 

 Groton, Chelmsford, Medford, et al. Not very common. May- 

 June. 



P, Pennsylvanica, L. Wild Red Chekrt. 

 Not uncommon ; abundant in the N. W. towns. May. 



P. Virginiana, L. Choke-Cherrt. 

 Common. May-June. 



P. serotina, Ehrh. Wild Black Cherrt. 

 Common. May-June. 



P. Avium, L. English Cherry. 

 Often spontaneous in copses, and apparently established. May. 



Neillia, Don. 



iV. opulifolia, Benth. & Hook. (Spiraea opulifolia, L., Man.) Nine- 

 Bark. 



Cambridge (C. E. Perkins); Melrose (L. L. Dame). Escapes. 

 June. 



Spie^a, L. 



S. salicifolia, L. Meadow-Sweet. 

 Very common. July-Aug. 



