A. VULGARIS. 

 Table 6. — Variation in the subspecies of Artemisia vulgaris — Continued . 



• Type of A. herrioli Rydberg, minor variation 27. 



• Duplicate type of A. atomi/era Piper, minor variation 4. 

 '° Includes several specimens referable to minor variation 8, 



A. carrulhi Wood. 

 " Minor variation 5, A. bakeri Greene. 

 " Type of A. coloradensis Osterhout, minor variation 9. 

 " Type of A. pringlei Greenman, minor variation 64. 



' The lower numbers sometimes aYe doubtless due to loss 



of flowers in pressing. 

 ' Minor variation 61, same as A. plati/ph]/lla Rydberg. 



• Type of A. floccosa Rydberg, minor variation 19. 



• Type of subspecies candicans (Rydberg). 

 ' Type of A. aradlenta Nelson, minor variation 25. 



• Minor variation 53, A. michauxiana Besser. 

 ' Minor variation 30, A. incompta Nuttall. 



ECOLOGY. 



The subspecies of Artemisia vulgaris of the greatest ecological importance are hetero- 

 phylla, ludoviciana, gnaphalodes, mexicana, and wrighti. These are all typically repre- 

 sentative of the species in the presence of rootstocks, vigorous growth, and late blooming. 

 As a consequence, they form societies in the late summer and autumn aspect of the climax 

 grassland, and persist for a long time as relicts of this formation in cultivated regions. 

 The similarity in their behavior is perhaps to be ascribed to their close relationship, and 

 may explain their distribution, as they appear to be mutually exclusive to a high degree. 

 They follow the grassland into the savannahs and parks of the foothill and montane 

 zones, reaching the maximum elevation at about 9,000 feet in the Rocky Mountains. 



Artemisia v. gnaphalodes is most characteristic of the true prairies, but is also an impor- 

 tant society of the subclimax and mixed prairies. Like its relatives, it is strongly grega- 

 rious, owing to its stout rootstocks, and the society often has the appearance of many 

 scattered clans. Ludoviciana is more typical of the foothill portions of the mixed prairie 

 and runs high up in the great mountain parks, such as Estes Park. It tolerates consider- 

 able shade, and is an important feature of the ground-cover of yellow-pine woodland. 

 The rootstocks are less stout than in gnaphalodes, and the plants make a more uniform 

 society. In the mixed prairies of northern New Mexico and Arizona, ludoviciana is 

 largely replaced by mexicana and especially wrighti, with essentially the same ecological 



