MIDDLESEX FLORA. 31 



S. tomentosa, L. Hardhack. 

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

 Aug. 



POTERIUM, L. 



P. Canadense, Benth. & Hook. Canadian Burnet. 

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



Agrimonia, Toum. 



A. Eupatorla^ L. Agrimony. 

 Not uncommon, July-Sept. 



Geum, L. Avens. 



G. album, Gmel. 



Rather common. July-Aug. 

 G. Virginianum, L. 



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



Thos. Morong). June-July. 

 G. 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. Water or Purple Avens. 



Not uncommon. May-June. 

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



Concord, introduced from Wisconsin by Minot Pratt. May. 



POTENTILLA, L. CiNQUE-FOIL. 



P. Norvegica, L. 



Rather common. July-Sept. 

 P. Canadensis, L. Common Cinque-foil. Five-Finger. 



Very common. Apr.-July. 

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



Very common. May-July. 

 P. argentea, L. Silvery Cinque-foil. 



Common. June-July. 

 P. arguta, Pursh. 



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



Swan) ; Melrose (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. Shrubby Cinque-foil, 



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



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



