MIDDLESEX FLORA. 31 



S. tomentosa, L. Haedhack. 

 Very common. A white variety in Westford (C. "W. Jenks). July- 

 Aug. 



POTERIUM, L. 



I^. Canadense, Benth. & HooIj. Canadian Buknet. , 



Dracut (Dr. C. W. Swan) ; Littleton (C. E. Perkins). Scarce. 



A&BiMONiA, Toum. 



A. Eupatoria, L. Agkimont. 

 Not uncommon, July-Sept. 



GrETJM, L. AVENS. 



G. aibum, Gmel. 



Bather common. July-Aug. 

 G. Virginianum, L. 



Maiden (F. S. Collins) ; Cambridge (C. E. Perkins) ; Ashland (Eev. 



Thos. Morong). June-July. 

 C strictum, Ait. 



Somerville (Bigelow's Fl. Bost.) ; Chelmsford and Tewksbury (Dr. 



C. W. Swan) ; Medford (Mrs. P. D. Richards) ; et al. July. 

 G. rivale, L. Watee oe Pttrple Avens. 



Not uncommon. May-June. 

 *G. triflorum, Pursh. " Called in the West, Old Maid's Feizzles." 



Concord, introduced from Wisconsin by Muiot Pratt. May. 



POTENTILLA, L. CiNQUB-POIL. 



P. Norvegica, L. 



Kather common. July-Sept. 

 P. Canadensis, L. Common Cinque-poil. Fivb-Fingee. 



Very common. Apr.-July. 

 P. Canadensis, L., var. simplex, Torr. & Gray. 



Very common. May-July. 

 P. argentea, L. Six-teet Cinque-foil. 



Common. June-July. 

 P. arguta, Pursh. 



Westford (Misses Fletcher and Hodgman) ; Chelmsford (Dr. C. W. 



Swan) ; Meh:ose (Rev. Thos. Morong) ; Concord (Thoreau). 



Not very common. June. 

 P. Anserina, L. Silver-weed. 



Marshes in Maiden, Medford, Everett and Cambridge. June-July. 

 P. fruticosa, L. Sheubbt Cinque-foil, 



Reading, rare (W. H. Manning); Concord, rare (Minot Pratt); 



Groton, abundant (C. W. Jenks). June-Aug. 



