A. VULGARIS. 

 Table 6. — Variation in Vie ttibapeeiea of Artemisia vulgaris — Continued. 



99 



Herbarium. 



No. of 

 bracts. 



No. 

 of ray- 

 flowers. 



No. 

 of disk- 

 flowers.' 



Total 

 flowers.' 



Length 

 of disk- 

 coroUa. 



Subspecies mexicana: 



Durango, Mex 



Alvarei, Mex 



Chihuahua, Mez 



Jalisco, Mex 



Comanche Spring, Tex . . . 

 Lincoln County, N. Mex. 

 Socorro County, N. Mex . 



91176 UC 



135371 UC 

 135375 UC 

 135374 UC 

 147496 UC 

 135373 UC 



135372 UC 



11 13 



15 



9 10 



10 11 

 9 U 



13 



11 13 



8 9 



8 



8 9 



7 8 

 4 6 



8 9 

 7 8 



16 18 

 16 

 9 11 

 9 10 

 4 7 



12 16 



13 13 



23 27 

 23 

 17 20 

 16 18 

 8 13 

 20 25 

 20 21 



mm. 

 2.4 



Average. 



U 



11 



18 



Subspecies wrighti:" 



Black Cafion, Colo." 



Marshall Pass, Colo 



Pagosa Spring, Colo 



Dale Creek, Colo." 



Costilla County, Colo 



La Veta Pass, Colo 



Do 



San Juan Valley, Colo 



San Juan Mountains, Colo . . . . 

 Southeastern Utah 



Do 



Do 



Desert Region 



San Francisco Mountain, Aris. 



Do 



Flagstaff, Ariz 



Chihuahua" 



34510 UC 

 34515 UC 

 34520 UC 

 Oster. 2010 



11092 CI 



11093 CI 



11094 CI 

 11122 CI 

 11104 CI 



175395 UC 



NY 



NY 



91219 UC 



135407 UC 



11183 CI 



193609 UC 



Gr 



7 9 



10 13 

 12 8 



11 11 



8 10 



9 10 

 10 9 

 14 9 



9 11 

 8 6 



8 10 

 8 9 

 14 13 



Average. 



8 11 

 11 9 



7 6 



8 8 

 14 12 

 16 13 

 10 9 



9 7 



7 8 

 6 6 



6 5 



8 10 



7 7 

 4 5 



14 12 

 6 7 

 18 16 



14 10 



16 11 



8 6 



9 10 



18 21 



17 14 



15 14 



16 19 

 10 12 



7 10 



7 6 



19 18 



8 4 

 5 6 



16 16 

 4 6 

 16 18 



22 20 

 27 20 

 15 12 

 17 18 



32 33 



33 27 

 25 23 

 25 26 

 17 20 

 13 16 

 13 11 

 27 28 

 15 11 



9 11 

 30 28 

 10 13 



34 34 



2.2 

 2,0 

 1.7 

 2.2 

 2.6 



2.2 

 2.0 

 2.0 

 2.2 

 2.1 

 2.0 

 2.2 

 2.4 

 2.1 

 2.2 

 2.3 

 2.1 

 2.0 

 1.8 

 2.0 

 2.0 

 1.9 



12 



21 



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



' Duplicate type of A. atomifera Piper, minor variation 4. 

 '° Includes several specimens referable to minor variation 8, 



A. carruthi Wood. 

 " Minor variation 5, .4. bakeri Greene. 

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

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



' The lower numbers sometimes are doubtless due to loss 



of flowers in pressing. 

 ' Minor variation 61, same as A. platyphylla Rydberg. 



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

 •Type of subspecies candicans (Rydberg). 



• Type of A. gracilenta 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 



