90 FLORA. OF THE UPPER SUSQUEHANNA. 



R. Britannica L. Great Water- Dock. Susquehanna, plentiful, 

 Graves. Elmira, infrequent, Lucy. 



R. verticillatus L. Swamp Dock. Water Dock. Common in 

 swamps and along ditches and streams. 



R. crispus L. Ctrled Dock. Yellow Dock. Common in 

 waste places everywhere. 



R. obtusifolius L. Bitter Dock. Not uncommon in gardens 



and lields. 



R. sanguineus L. Red Dock. Rather rare. Noyes Island, 

 Millspaugh. Apalachin, Fenno. Sayre, Barbour. 



R. Acetosella L. Field Sorrel. Horse Sorrel. Sheep Sorrel. 

 Common everywhere. Most abundant in rather dry sterile soil. 

 Often overruns large areas and is difficult to exterminate. The 

 whole plant has an acid taste. 



POLYGONUM L. 



P. aviculare L. Bird's Knot-grass. Low Knot-weed. Abun- 

 dant m old dooryards, along paths, and in waste grounds. Well 

 known. 



P. erectum L. Tall Knot weed. Less common than the pre- 

 ceding, and found in the same places. Whole plant larger and 

 more erect. 



P. Pennsylvanicum L. Smart -weed. Common in wet grounds. 



P. amphibium L. Water Smart-weed. Not uncommon in wet 

 places. Rare. Lucy. 



P. emersum (Michx.) Britton. Chemung river at Harrington's 

 Ford. Lucy. Binghamton, Clute. The only stations. (P. 

 Muh! enter gil Watson. ) 



P. orientate L. Prince's Feather. An occasional escape from 

 cultivation, half naturalized along streets and in waste grounds. 



P. Persicaria L. Lady's Thumh. Heart Weed. Very common 

 in all waste places Leaves marked with a dark triangular spot. 



P. Hydropiper L Common Smari-wekd. Water Peiter. Very 

 common in moist or wet soil. 



