120 TWELFTH ANNUAL REPORT. 



P. erectuin. L. (P. aviculare. L., var. erectum, Roth.) Erect Knotorrass. 

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

 etc.; Worthington (common), Foote; Crookston, Grand Forks, and elsewhere in the 

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



P . raniosissiiuuui, Michx. Polygonum. 



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

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

 and west. 



P. teime, Michx. Slender Knotgrass. 



Lapham. Lake Pepin, Miss Manning; rocky hills. Mound, Rock county. Leiberg; 

 lake of the Woods, Da u'sod. Rare. South aud west. 



P. arifoliiini, L. Halberd-leaved Tear-thumb. 



« 

 Blue Earth county, Gedge. Infrequent. 



P. s'ag'ittatiim, L. Arrow-leaved Tear- thumb. 



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

 Roberts; Todd county, etc. (common), Upham; Stearns county, Campbell; Auoka 

 county, also New Ulm, Jimi. 



P. Convolvidus, L. Black Bindweed. 



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

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



P. cilinode, Michx. Polygonum. 



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

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



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

 Common, or frequent, tliroughout the state. 



FAGOPYRUM, Tourn. Buckwheat 



F. esculentum, Moench. Buckwheat. 



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



RUMEX, L. Dock. Sorrel. 



R. longifolius, DC. Dock. 



Hennepin county, Hei-rick. Infrequent. Northwest. 



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



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

 Isanti county, Upham; Stearns county, 3J rs. BiaisdeH; Anoka county, also New Ulm, 

 Juni; White Bear lake, Ramsey county, Kellcij;l3ike Pepin, Miss Manning; Blue Earth 

 county, Leiberg. 



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

 leaved Dock. 

 Upper Mississippi river, Garrison; Minneapolis, Kassube; Cannon River Falls, 

 Blake, Sandherg; lake Pepin, Miss Manning; y\'mona connty, Holzinger; Blue Earth 

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



R. salicifolius, Weinman. White Dock. 



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

 [James river, Dakota, Geyer.] 



R. verticillatiis, L. Swamp Dock. 



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

 Miss Butler; Blue Earth county, Leiberg; New Ilm, Juni. 



