255] FLORA OF BOULDER, COLORADO IO7 



344. P. Douglasii Greene. DOUGLAS'S KNOTWEED. 

 Common in open, especially sandy places throughout, 5100*- 



loooo ft. (Daniels, 958). 



VERMONT to BRITISH COLUMBIA ; NEW YORK to NEW MEX- 

 ICO and CALIFORNIA. 



344a. P. Douglasii consimile (Greene) Small [P. consimile 

 Greene]. BRANCHED DOUGLAS'S KNOTWEED. 



Gregory Canon, 6000-6300 ft. (Daniels, 546). Lower Boul- 

 der Canon (Rydberg). 



Range of the type? 



128. PERSICARIA Adans. SMARTWEED. LADY'S 

 THUMB. 



345. P. emersa (Michx.) Cockerell. Nov. comb. [Polygonum 

 Muhlenbergii S. Wats; Polygonum emersum (Michx.) 

 Britton]. MUHLENBERG'S LADY'S THUMB. 



Along ditches and in swales in the plains, 5100-6000 ft. (Dan- 

 iels). 

 MAINE to BRITISH COLUMBIA ; VIRGINIA to CALIFORNIA and 



346. P. lapathifolia (L.) S. F. Gray [Polygonum lapathifo- 

 lium L.]. DOCK-LEAVED LADY'S THUMB. 



Swales and ditches in the plains, 5100-6000 ft. (Daniels, 

 506). 



EUROPE: ASIA: NORTH AMERICA. 



347. P. Persicaria (L.) Small. [Polygonum Persicaria L.]. 

 COMMON LADY'S THUMB. 



Common in waste places, and along ditches and in swales, 

 5100-6000 ft. (Daniels, 517). 



EUROPE, thence to NORTH AMERICA. 



348. P. punctata (Ell.) Small [Polygonum punctatum Ell.; 

 Polygonum acre H. B. K.]. WATER SMARTWEED. DOTTED 



WATER PEPPER. 



Margins of ponds, in swales and springy grounds, 5100-6000 

 ft. (Daniels, 798). 

 NORTH AMERICA: CENTRAL AMERICA: SOUTH AMERICA. 



