gramic way. Williams 2 says the timber-line barely averages 



1. Op. cit. 



2. Williams, E. F. Floras of Mt. Washington and Mt. Ktaadn. Rhodora 3 : 1600 

 65. 1902. 



3,100 feet in the great basin and 2,200 on the southern slopes ; he 

 adds: "this last being partly due, however, to their excessive 

 steepness." 



It would appear from the above discussion that this so-called 

 "timber-line" is more apparent than real and has no relation to 

 climatic conditions, as most writers have implied, but is largely 

 determined by the steepness and the resulting avalanches on the 

 slopes and is in reality the limit of large trees. It was shown 

 above that the limit of the Krummholz upon the upper slopes was 

 not climatic but that the question of time and edaphic conditions 

 had alone retarded its further advancement. There is then no 

 true climatic timber-line upon Ktaadn any more than "upon the 

 other mountains of Maine, Black Cap, Waldo, Desert, and others 

 of far lower altitudes, and it is largely the element of time that 

 retards the forestation of the very summit. 



(f). The Roches Moutonees Society. In the Northwest basin 

 are' two rock hills rising some 20-25 f eet above the general level 

 of the shelf. With their sloping sides and flat glaciated tops 

 they present a plant society most unique. Bare in places, they 

 are almost entirely covered with a typical heath formation. The 

 drainage is excessive and the conditions extremely xerophytic. 

 The flat tops are dominated by Kalmia angustifolia, Cassan- 

 dra calyculata, and Ledum latifolium. It bears a most striking 

 resemblance to an old sphagnum bog. In places tussocks of 

 sphagnum appear and associated with it is V actinium Vitis- 

 Idcea. Cladonia rangiferina, and its less common variety alpes- 

 tris are abundant. Around bare rocks Vaccinium uliginosum 

 abounds. Little remains to tell of the early stages of this unique 

 association. It is however clear that it has passed through the 

 crustaceous-lichen and reindeer moss stages. The heath stage 

 corresponds in sequence to that of the Alpine-Tundra which for 

 some reason has failed to develop here. 



Covering the steep sides of those roches moutonnees and the 

 basin in general, is the mesophytic Pic ea- Abies forest with its 



38 



