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, Pittsfleld. 
P. Muhlenbergii (Meisn.) Wats. — {Persicaria Muhlenbergii 111. 
Fl. ed. 2.) 
Muddy shores of ponds, and marshes; frequent in the valley. 
P. ORiENTALE L. Prince's Feather. — (Pcrsicaria orientalis 111. 
Fl. ed. 2.) 
Occasionally persistent in waste ground, Stockbridge. 
P. pennsylvanicum L., var. laevigatum Fernald. Pink Knot- 
weed. — (P. jmmsijh'anicum Man. ed. 7 in part, rid. Rhodora 19: 
73, 1917; Pcrsicaria pcnnsuhanica 111. Fl. ed. 2.) 
Low ground; common. 
Leaves glabrous or at most sparsely strigose on the midrib beneath. 
P. Persicaria L. Lady's Thumb. — {Persicaria jyersicaria 111. Fl. 
ed. 2.) 
Waste places and low ground; common. 
P. sagittatum L. Arrow-leaved Tear-thumb. — ( Tracaulon 
sagittafum 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 IMichx. — Open sterile soil; occasional in the southern 
part of the ^■alley. Alford; Sheffield. 
P. virginianum L. — ( Tovara virginiana 111. Fl. ed. 2.) 
Alluvial thickets; frequent in the southern part of the valley and 
along the Deerfield Ei^•er, Florida. 
RUMEX. Dock. 
R. Acetosa L. Garden Sorrel. — Fields; occasional. Lee; 
Lenox; Stockbridge. 
R. Acetosella L. Sheep Sorrel. — Cultivated ground, old fields, 
rocky ledges; common. 
R. britannica L. Great Water Dock. — Swamps; common. 
