HOFFMANN: FLORA OF BERKSHIRE COUNTY. 259 



Borders of swamps and muddy shores; frequent in the valley. 



P. lapathifolium L. Dock-leaved Persicaria. — (Persicaria 

 lapathifoHa 111. Fl. ed. 2.) 



Wet places; common. 



var. salicif olium Gibthorp. — (P. tomentosum Schrank, var. incanum 

 Man. ed. 7.) 



Sandy shore of Pontoosuc Lake, Pittsfield. 



P. Muhlenbergii (Meisn.) Wats. — (Persicaria Muhlenhergii 111, 

 Fl. ed. 2.) 



Muddy shores of ponds, and marshes; frequent in the valley. 



P. orientale L. Prince's Feather. — {Persicaria orientalis 111. 

 Fl. ed. 2.) 



Occasionall}'^ persistent in waste ground, Stockbridge. 



P. pennsylvanicum L., var. laevigatum Fernakl. Pink Knot- 

 weed. — {P. pcnnsyh-anicum Man. ed. 7 in part, vid. Rhodora 19: 

 73, 1917; Persicaria 'pennsyhanica 111. Fl. ed. 2.) 



Low groimd; common. 



Leaves glabrous or at most sparsely strigose on the midrib beneath. 



P. Persicaria L. Lady's Thumb. — {Persicaria persicaria 111. Fl. 

 ed. 2.) 



Waste places and low ground; common. 



P. sagittatum L. Arrow-leaved Tear-thumb. — {Tracaulon 

 sagittatum 111. Fl. ed. 2.) 



Low ground; common. 



P. scandens L. Climbing False Buckwheat. — ( Tinaria scan- 

 dens 111. Fl. ed. 2.) 



Alluvial thickets; frequent in the valley. 



P. tenue Michx. — Open sterile soil; occasional in the southern 

 part of the valley. Alford; Sheffield. 



P. virginianum L. — {Tovara virginiana 111. Fl. ed. 2.) 



Alluvial thickets; frequent in the southern i)art of the valley and 

 along the Deerfield River, Florida. 



RUMEX. Dock. 



R. AcETOSA L. Garden Sorrel. — Fields; occasional. Lee; 

 Lenox; Stockbridge. 



R. Acetosella L. Sheep Sorrel. — Cultivated groimd, old fields, 

 rocky ledges; common. 



R. britannica L. Gkeat Water Dock. — Swamps; common. 



