1921-22 



DEPARTMENT OF LANDS AND FORESTS 



247 



(2) Flora of the forest floor. — For the sake of acquiring a better knowledge 

 of the forest floor, and especially its "index" plants, an annotated and represent- 

 ative, though not exhaustive, collection of seed plants and ferns has been 

 assembled by Mr. H. P. Watson from the Temagami Forest Reserve — about 

 450 species in all. 



1. ^'Red branch'^ of balsam, pine, and arbor vitae, and "spike branch" of 

 spruce. 



"Red branch" of balsam is of frequent occurrence. The dead, red-needled 

 branches located here and there throughout a balsam tree are conspicuous 

 objects against the dark green setting of normal living foliage, and are bound to 

 attract attention. Various explanations to account for them have been offered; 

 one of the commonest theories is that of snow pressure. But this explanation 





big. 7. — Type 111: A butt rot of balsam. 



lacks proof. The most frequent cause is not snow pressure, but a combination 

 of two factors, namely insect-gnawing of the bark (which is almost invariably 

 restricted to the lower surface, and is by no means a girdling) and the sub- 

 sequent "drying out" of the living tissues at the same level, a process that is 

 favoured by the action of frost, and by the inactivity of these tissues during the 

 fall and winter. 



An examination of the branch at the base of the dead portion almost in- 

 variably shows a more or less extensive spot from which the bark has been re- 

 moved, a ragged-edged wound at once suggesting the gnawing of some small 

 animal. This spot is usually on the under side; it never extends more than half 

 way around the branch and usually much less, so that the branch is not girdled. 



