30 MIDDLESEX FLORA. 



S. subvillosa, L. 



Westf ord, near woollen-mills (Dr. C. W. Swan) . Adv. from Eu. 

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

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



ROSACES. ROSE FAMILY. 



PRUNUS, Tourn. 



P. Americana, Marsh. WILD YELLOW or RED PLUM. 

 Concord (Minot Pratt) ; Medf ord (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. 



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

 mington (L. L. Dame). Rare. 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 CHERRY. 



Groton, Chelmsford, Medford, et al. N"ot very common. May- 

 June. 



P. Pennsylvanica, L. WILD RED CHERRY. 

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



P. Virginiana, L. CHOKE-CHERRY. 

 Common. May-June. 



P. serotina, Ehrh. WILD BLACK CHERRY. 

 Common. May-June. 



P. AVIUM, L. ENGLISH CHERRY. 



Often spontaneous in copses, and apparently established. May. 



NEILLIA, Don. 



N. opulifolia, Benth. & Hook. (Spiraea opulifolia, L., Man.) NINE- 



BARK. 



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



June. 



SPIRAEA, L. 

 S. salicifolia, L. MEADOW-SWEET. 



Very common. July-Aug. 



