.MARYLAND WEATIIEB SERVICE 429 



POLYGONACEAE. 



Rumex acetosella L. Sheep Sorrel. 



Throughout the state; in cultivated grounds; common. 



Rumex verticillatus L. Swamp Dock. 



Coastal Zone; in moist swamps and ponds; infrequent. 

 Dorchester County, Little Blackwater River (1598). 



Rumex crispus L. Curled Dock. 



Throughout the state; in cultivated grounds; common. Introduced from 

 Europe. 



Polygonum pennsylvanicum L. Pennsylvania Knotweed. 



Throughout the state; in moist cultivated grounds; common. 



Polygonum hydropiperoides Michx. Mild Water Pepper. 



Throughout the state; in marshes, swamps and open wet situations; 

 common. 



Polygonum punctatum Ell. (acre H. B. K.) Water Smart-weed. 



Throughout the state; in open situations; common. 



Polygonum virginianum L. Virginia Knot-weed. 



Throughout the state; in moist forests; frequent. 



Polygonum aviculare L. Knot-grass. 



Throughout the state; in cultivated grounds; common. 



Polygonum amphibium L. 

 Coastal Zone. 



Polygonum maritimum L. Seaside Knotweed. 



Coastal Zone; in salt and brackish marshes; infrequent. 

 Worcester County, Ocean City (1230). 



Polygonum erectum L. 



Throughout the state; in cultivated and waste grounds; common. 



Polygonum tenue Michx. Slender Knotweed. 



Baltimore County, Bare Hills (Robert K. Miller). 



Polygonum convolvulus L. Black Bindweed. 



Throughout the state; in cultivated grounds; common. Introduced from 

 Europe. 



Polygonum scandens L. Climbing False Buckwheat. 



Throughout the state; in cultivated grounds; frequent. 



Polygonum sagittatum L. Arrow-leaved Tear-thumb. 



Throughout the state; in marshes, swamps and open wet situations; 

 common. 



Polygonum arifolium L. Halberd-leaved Tear-thumb. 



Throughout the state; in marshes, swamps and open wet situations; 

 common. 



