236 UNIVERSITY OF MISSOURI STUDIES [37^ 



1008a. O. involucrata Nutt. x Bidens comosa (Gray) 

 Wiegand. 

 Along the Wabash railroad, July, 1903. 



1009. O. discoidea T. & G. [5. discoidea (T. & G.) Britton]. 

 Small tickseed. 



Low grounds. 



Massachusetts to Michigan and Missouri; North Caro- 

 lina to Texas. 



413. BIDENS L. Beggar-ticks. 



loio. B. frondosa L. Common stick-tights. 

 Common in waste places and low grounds. 

 New Brunswick to South Dakota; Florida to Texas. 



loii. B. connata Muhl. Swamp beggar-ticks. 



Low grounds; common and varying into the next. 



New Hampshire to Minnesota and South Dakota; North 

 Carolina to Missouri. 



1012. B. comosa (Gray) Wiegand \B. C07i?iata comosa Gray]. 

 Large swamp beggar-ticks. 



Very common in low grounds. 



Maine to Minnesota and Colorado; Georgia to Louis- 

 iana. 



1013. B. cernua L. Bur-marigold. 

 Infrequent in low grounds. 



Nova Scotia to Oregon; North Carolina to Missouri 

 and Colorado: Europe and Asia. 



1014. B. bipinnata L. Spanish needles. 

 Common in low grounds and waste places. 



Rhode Island to Nebraska; Florida to Arizona, Mex- 

 ico and Tropical America. 



414. HELENIQM L. Sneezeweed. 



1015. H. tenuifolium Nutt. Fine-leaved sneezeweed. 

 Flats of Hinkson creek; very rare. 



Virginia to Michigan and Kansas; Florida to Texas. 



