160 STATE HORTICULTURAL SOCIETY 



2053. R. obtusifolius, L. Broad Leaved Dock. 

 Introduced from Europe; common. 



2054. R. pericariodes, L. Golden Dock. 

 In shady soil, not common. 



Fagophrum, Gaertn. 



2055. F. fagopyrum, (L.) Karst. Buckwheat, 



Not uncommonly naturalized in waste places. 

 Polygonum, L. 



2056. P. amphibium, L. Water Persicaria. 

 In water and mud, infrequent. 



2057. P. hartwrightii, A. Gray. Hart Wright's Periscaria. 

 Margin of ponds, not common. 



2058. P. emersum, (Michx.) Britt. Swamp Persicaria. 



Common in ponds. 



2059. P. incarnation. Ell. Pink Persicaria. 

 Common in wet soils. 



2060. P. lapathifolium, L. Pale Persicaria. 

 Common in waste places. Introduced. 



2061. P. lapathifolium nodosum, Pers. 

 Introduced from Europe. 



2062. P. pennsylvanicum, L. Pennsylvania Smartweed. 

 Common in moist soil. 



2063. P. persicaria, L. Lady's Thumb. 

 Introduced weed. Waste places, common. 



2064. P. hydropiper, L. Smartweed. 

 In moist places, common. 



2065. P. virginianum, L. Virginia Knotwood. 

 Common in woods. 



2066. P. aviculare, L. Doorweed. 

 A common door yard weed. 



2067. P. littorale, Link. Shore Knotweed. 

 Not common. 



2068. P. camporum, Meisn. Prairie Knotwood. 

 In dry sandy soil. 



2069. P. tenue, Michx. Slender Knotweed. 

 Common in dry sandy soil. 



