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E. LUCY BRAUN 



furnish soil and a foothold for herbaceous plants, the presence 

 of pockets comes to be of less importance. Late in the first moss 

 stage patches of herbaceous plants, among which Sedum ter- 

 naium is most prominent (fig. 1), begin, to compete with the 

 mosses. The most rapid advance of herbaceous plants is made 

 on gentle slopes and ledges. 



On southerly slopes and in all dryer situations, the most 



Fig. 3. V.'alking fern and Mitella on a northward facing moss-covered rock. 



advanced herbaceous stage seen is a xero-mesophytic closed 

 association in which Sedum is dominant throughout the year. 

 With the Sedum, and of varying importance at different seasons, 

 are Cystopteris fragilis, Aquilegia canadensis, Silene virginica, 

 Aster Shortii, Viola Rafinesquii and V. striata, Arabis Drum- 

 mundi, Heuchera americana, and a few individuals of a number 

 of other less characteristic plants. 



On northerly slopes the earlier herbaceous stages are con- 

 temporaneous with the lichen and moss stages. Throughout 



