118 



GENUS ARTEMISIA. 



experiments of Gmelin, who found that the seeds of odorous plants produced inodorous 

 individuals when grown in the botanical garden (according to Ledebour, Fl. Rossica 

 2:563, 1846). In the latest account of our species (Rydberg, N. Am. Fl. 34:244 to 285, 

 1916), aromatica is retained as a species and separated from the Old World dracunculus 

 on two principal characters: (1) the outermost bracts are said to be almost as long as the 

 innermost instead of only about one-half as long; (2) the flowers are given as 30 to 100 

 in number as compared with 20 to 40 in dracunculus. 



The supposed difference in the bracts is not evident. In fact, a close examination of 

 a series of collections indicates the same relative length of outer and inner bracts in 

 American and European material. As to the number of flowers, the figures just quoted 

 show a sufficient overlapping to suggest the doubtful value of this criterion and when a 

 large series is examined it is found that the distinction almost completely vanishes. 



Table 10. — Variation in the sitbspeeies of Artemisia dracunculus. 



