ABIETINE.E, THE FIR AND PINE TRIBE. 59 



Tribe 1.— ABIETINE^E— The Fir and Pine Tribe. 



All the species belonging to the Fir and Pine tribe are trees 

 with erect trunks, regularly furnished with branches from the base 

 to the summit, which gradually contract in length from the bottom 

 upwards ; the trees, therefore, present a strictly pyramidal or 

 conical outline during the period of active growth, which is gene- 

 rally very rapid up to the time of their maturity. As they 

 become older, the lower branches, which very rarely attain a 

 timber-like size, as in many deciduous broad-leaved trees, die off. 

 Their duration, however, depends much on the situation of the 

 tree; if standing solitary, the lower branches are persistent many 

 years ; but when a number of trees are standing close together, 

 the lower branches are thrown off at an early period. 



In the former case, the persistency is favoured and prolonged by 

 free exposure to the air; in the latter, the throwing off is hastened 

 by the exclusion of it. The height of the trunk is influenced by 

 the persistency of the branches ; while these remain in health and 

 vigour, the trunk increases in height less rapidly than when the 

 lower branches are thrown off in the early life of the tree. Hence 

 it is evident, that in planting trees of the Fir and Pine tribe for 

 ornamental purposes, they shoidd have a greater space assigned to 

 them than the area usually covered by the spread of their lower 

 branches ; but if planted for the sake of their timber, or to secure 

 straight erect trunks as free from knots and protuberances as possible, 

 they should be planted not much farther apart than is sufficient to 

 allow their roots to take a firm hold in the soil. 



In their maturity, the Firs, Larches, and Araucarias divested of 

 their lower branches, are trees with thin spiry tops; the Pines 

 and Cedars, in their old age, form rounded tops by the branches 

 near the summit becoming thickened, and by the leader gradually 

 ceasing to ascend. In Abies the bark is never very thick or 

 tough, but in several species of Pinus, P. pinea for example, it 

 becomes, on the contrary, very thick, rigid, cracked, and deeply 

 furrowed; in other species, as the Scotch Pine, it takes a reddish 

 tinge, and in the Lace-bark Pine of China (P. Bungeana), and 

 also Captain Gerard's Pine (P. Gerardiana), it is grey or milky 

 white, and peels off like that of the Birch or Arbutus. Aged 



