106 UNIVERSITY OF MISSOURI STUDIES [254 



127. POLYGONUM L. Knotweed. 



336. P. erectum L. Erect knotweed. 



Along the railroad in Boulder Canon, 5500 ft. (Daniels, 580). 

 Maine to Alberta ; Georgia to Arkansas and Colorado. 



337. P. buxiforme Small. Box-like knotweed. 



Bear Canon, and all waste places, 5100-10000 ft. (Daniels, 



698). 



Ontario to Washington ; Virginia to Texas and Nevada. 



338. P. aviculare L. Doorweed. 



Common about houses, along railroads, and in all waste 

 places, 5100-8000 ft. (Daniels, 582). 

 Asia: Europe: North America. 



339. P. ramosissimum Michx. Bushy knotweed. 

 Common along railroads and roads, and in low weedy 



grounds, 5100-10000 ft. (Daniels, 519). 



Minnesota to Washington ; Illinois to New Mexico and 

 Nevada ; Maine to New Jersey along the coast. 



340. P. Sawatchense Small. Saguache knotweed. 



High mesas at foot of the Flat-irons, 5700-6000 ft. (Dan- 

 iels, 178). 



South Dakota to Washington; Colorado to Arizona and 

 California. 



341. P. eonfertiflorum Nuttall [P. IVatsonii Small]. Wat- 

 son's knotweed. 



About the quarries at foot of the Flat-irons, 5700-6000 ft. 

 ( Daniels, 660). 

 Montana to Washington ; Colorado to California. 



342. P. unifolium Small. One-leaved knotweed. 

 Aspen bogs at Glacier Lake, 9000 ft (Daniels, 672). 

 Montana to Colorado. 



343. P. Engelmannii Greene [P. tenue microspermum 

 Engelm.]. Engelmann's knotweed. 



Sandy stream-flats, especially common along the railroad in 

 Boulder Canon, 5100-10000 ft. (Daniels, 568). 

 Montana and Colorado to British Columbia. 



