Wiegand: Some Species of Bidexs 411 



Maine to West Virginia, westward to Minnesota and Colorado 

 and from Western Georgia (Chapman), Louisiana. 



Specimens examined from : — Maine : Orono, Fcrnald, Mass^l- 

 chusetts : Revere, //. A. Young. New^ York : Torrcy, Briiton^ Hulst 

 (many from central N. Y.). New Jersey : Parker, Nash. West 

 Virginia : near Bucklin, P<^/^r/{\ Tennessee: Ruth, no. 32. Ken- 



i 



tiicky : Short. Ohio: Werner, Lea, no. 167 (Torn Herb.). Illi- 

 nois : Chapman, DeForest. Minnesota : Hohinger. Kansas : Nor- 



ton, no. 281, Riley Co. Missouri : Bush, no. 167 (in pai 



Louisiana : Hale, Colorado : Lincoln Co., Rydbcrg, no. 190. 



Bidens comosa acuta var. nov. 



Habit as in the type, but leaves sessile or nearly so : heads 

 much broader (broader than high, 10-20 mm. broad) and achenes 

 more spreading ; outer involucral bracts only twice the length of 

 the disk or less, conspicuously spreading, lanceolate, acute and 

 apiculate ; inner narrowly triangular-lanceolate, acute. 



Kansas and Missouri. 



Specimens examined : — Kansas : Manhattan, Norton, 1892. 

 Missouri: Engelmann, St. Louis, 1866. Missouri: Bush, no. 164, 

 Jackson Co. ; nos. 31 and 49, Courtney Co. 



Bidens comosa is common throughout the Middle States and 

 Mississippi Valley growing preferably in rather dry soil. Its usual 

 habitat is along roadsides where the soil is rich, or on the sandy 

 margins of lakes and rivers. 



When growing undisturbed it often becomes so numerous as 

 to form dense patches to which the pale upright stems and short 

 branches give a characteristic appearance. Certain specimens 

 however from widely separated localities (the Short, Hale and 

 Werner specimens cited above, and others) present an entirely dif- 

 ferent aspect. The stems are decumbent at the base ; the leaves 

 are shorter, blunter, more sparsely and bluntly toothed or the 

 upper entire ; and the mvolucre of the long-peduncled heads is 

 very foliaceous, with broad obtuse bracts. At first it seemed 

 proper to separate this form as a distinct variety, but in the study 

 of specimens from the vicinity of Ithaca similar plants w^ere found 

 but apparently always as a second growth after the main stem had 

 been Injured or cut away by the mower. It may be possible that 

 the similar variation in B, connata is from a like cause. The same 

 variation also occurs in the var. acuta. 



