14 TRANSACTIONS OF ROYAL SCOTTISH ARBORICULTURAL SOCIETY. 



certain trees gregarious in their character, while others are only 

 found scattered in forests of other trees 1 A complete reply to that 

 question cannot be given at present, but perhaps we shall be able 

 better to understand one of the factors which govern the habits of 

 trees in this respect, if you follow me for a few minutes into a 

 range of mountains called the Nilgiris, or Blue Mountains, which 

 are situated in the peninsula of India. This mountain range is 

 associated with the name of my dear late friend, Dr Hugh 

 Cleghorn, who repeatedly has been the President of your Society, 

 and whose services to Indian Forestry cannot be spoken of too 

 highly. 



These mountains have probably received their name from a 

 shrub, a species of Strobilanthes, which covers extensive areas on 

 the slopes, and which bears a profusion of blue flowers. Like 

 this one, other species of Strobilanthes also are gregarious, some 

 covering large areas in the open, while some form the underwood 

 in the forest. It is a remarkable fact, that most of the gregarious 

 species do not flower annually, but in periods, according to the 

 species, of from five to ten years. There is an underground 

 rootstock or rhizome, which annually sends up leaf-bearing stems. 

 When the rootstock has attained a certain age, flower-buds 

 instead of leaf-buds are formed on the branches, the plant is 

 covered with flowers, and after the seeds have ripened, it dies. 

 There seems to be a certain coincidence between gregarious habit 

 and periodical flowering. In a marked manner this shows itself 

 in the Beech, and in several coniferous trees, which are eminently 

 gregarious. There are no large Beech forests in Scotland, and the 

 circumstance may not be as familiar to you as it is to foresters 

 on the Continent, that the Beech does not bear a good crop of 

 seed every year, but that mast years occur at irregular intervals 

 of from five to ten years. Those trees and shrubs, which flower 

 periodically at regular or irregular intervals, on such occasions 

 produce such an abundance of seed that the thickets of young 

 plants kill out everything else, and thus grow up as pure woods. 



These remarks must suffice by way of introduction . The question 

 of gregarious and sporadically growing trees is a very large one, 

 which may well claim the interest of foresters and botanists. 



I desire now to draw your attention to several large areas 

 stocked with pure forests in Germany. You will, I feel sure, 

 excuse my speaking of the forests of my own country. In the 

 first place, I am more familiar with them ; and, in the second 



