MIDDLESEX FLOKA. 31 



S. tomentosa, L. HARDBACK. 



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, Tourn. 



A. Eupatoria, 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. 

 *#. triflorum, Pursh. u Called in the West, OLD MAID'S FRIZZLES." 



Concord, introduced from Wisconsin by Minot Pratt. May. 



POTENTILLA, L. ClNQUE-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. 



