108 FLORA OF WASHINGTON AND VICINITY. 



POLYGONACE^. 



Buckwheat Family. 



Polygonum orientale, L. Prince's Feather. 

 July. 



t Polygonum Pennsylvanicum, L. 



August. 



Polygonum incarnatum, Ell. 

 July, August. 



t Polygonum Persicaria, L. Lady's Thumb. 

 June, July. 



Polygonum Hydropiper, L. Common Smartweed, Water-Pepper. 

 August, September. 



Polygonum acre, H. B. K. Water Smartweed. 

 July. 



t Polygonum hydropiperoides, Miebx. Mild Water-pepper. 

 Carberry Meadows. August. 



Polygonum amphibium, L. Water Persicaria. 



Pond ou the Carberry Meadows; rare. Only seen once, July 17, 1881. 



Polygonum amphibium, L., var. terrestre, Willd. 

 Flats near the Outlet Lock. August. 



t Polygonum Virginianum, L. 



August. 



t Polygonum aviculare, L. Knotgrass. Doorweed. 

 June, July. 



t Polygonum erectum, L. [P. aviculare, L., var. erecium, Roth.] 

 July. 



t Poly gonum arifolium, L. Halberd- leaved Tear-Thumb. 

 September. 



+ Polygonum sagittatum, L. Arrow-leaved Tear-Thumb. 

 August, September. 



t Polygonum Convolvulus, L. Black Bindweed. 

 July to November. 



Polygonum dumetorum, L. Climbing False Buckwheat. 

 August, September. 



t Polygonum dumetorum, L., var. scandens, Gray. 



Fagopyrum esculentum, Moench. Buckwheat. 



Occasionally found in the vicinity of fields. August. 



Rumex Britannica, L. Pale Dock. 

 May 



