120 TWELFTH ANNUAL REPORT. 



P. erectiim, L. (P. avicu'are. L., var. erectum, Roth.) Erect Knotgrass. 

 Also common, or frequent : Winona, Blue Earth, Hennepin and Stearns counties, 

 etc. ; Wortliington (common), Foote; Urookston, Grand Forks, and elsewhere in the 

 Red river valley (common), Winchell; Pembina, Havard 



P. raniosissimuin, Michx. Polygonum. 



Brown county, Juni; Martin county, and Emmet county, Iowa (common), Cratty; 

 common from Jackson county westward and in the Red river valley, Upham. South 

 and west. 



P. teniie, Michx. Slender Knotgrass. 



Lapham. Lake Pepin, Mixs Manning; rocky hills, Mound, Rock county. LeWerg; 

 lake of the Woods, Dawson. Rare. South and west. 



J*, arifolium, L. Halberd-leaved Tear-thumb. 

 Blue Earth county, Oedge. Infrequent. 



P. sagittatum, L. Arrow- leaved Tear-thumb. 



Common near Stewart river (north shore of lake Superior), and at Minneapolis, 

 Roberts; Todd county, etc. (comnion), Upham; Stearns county, Campbell; Anoka 

 county, also New Ulm, Juni. 



P. Convolvulus, L. Black Bindiceed. 



Common, or frequent, throughout the state : troublesome in fields of grain by caus- 

 ing it, when beaten down by wind and rain, to remain so. 



P. cilinotle, Michx. Polygonum. 



Abundant north of lake Superior and in Carlton county, Juni, Roberts; upper Missis- 

 sippi river. Garrison; Stearns county, Mrs. Blaisdell. North. 



P. dumetoriiiii, L., var. scanden.s, Gray. Climbing False Buckwheat. 

 Common, or frequent, throughout the state. 



FAGOPYRUi>r, Tourn. Buckwheat 



F. esculentuin, Moench. Buckwheat. 



Occasionally adventive: Minneapolis, and Dakota, Nicollet and Blue Earth counties, 



RUMEX, L. Dock. Sorrel. 



R. longifolius, DC. Dock. 



Hennepin county, Hcrrick. Infrequent. Northwest. 



R. Britannica, L. (R. orbiculatus, Gray.) Great Water-Dock. 



North of lake Superior(common near Stewart river). Roberts; St. Croix river, Parry: 

 Isanti county, Upham; Stearns county, Mrs. Blaisdell; Anoka county, also New Ulm, 

 Juni; White Bear lake, Ramsey county, KeUcy;\a,ke Pepin, Miss Manning; Blue Earth 

 county, Leiberg. 



R. altissimiis. Wood. (R. Britannica, L., in Manual.) Pale Dock. Peach- 

 leaved Dock. 

 Upper Mississippi liver. Garrison; Minneapolis, Kassuhc; Cannon River Falls, 

 BJahe, Sandherg; lake Pepin, Miss Manning-, "Winona county, Holzinger; Blue Earth 

 county, Leiberg; Emmet county, Iowa (common), Cratty. South. 



R. salicifolius, Weinman. White Dock. 



Hennepin county, Herrick; Kittson county, Upham; Pembina, Chickcring, Havard. 

 [James river, Dakota, Geyer.] 



R. verticillatus, L. Swamp Dock. 



Upper Mississippi river Garrison; Isanti county, etc., Upham; West Saint Paul, 

 Miss Butler; Blue Earth county, Leihenj; New Llni, Juni. 



