PINACE^ 375 



resinosa. In 1916, 80,068 cords of wood of the Jack pine were 

 used for paper piilp.^ 



P. Banksiana is extremely hardy, and is said to grow on land 

 that is permanently frozen two feet beneath the surface. It 

 occurs on well-drained, sandy or rocky land from 100-1,200 ft. 

 above sea-level. Throughout life it is very intolerant of shade. 

 It is an abundant seed-bearer, even when very young, and good 

 seed years occur at intervals of 2-3 years. Naturally a short- 

 lived tree, its commercial age does not exceed 110 years, and 

 trees rarely exceed 150 years of age. Some attention has been 

 given to the species for forest planting in cold and exposed places 

 of the British Isles, but it should not be planted where a more 

 profitable species is likely to succeed, for it can have Httle or no 

 value as a commercial tree. 



Pinus Bungeana, Zuccarini. (Fig. 83.) 

 Lace-bark Pine. 



Piniis excorticata, Lindley and Gordon. Bunge's Pine. 



A tree 80-100 ft. high and 12 ft. in girth in China, or, in culti- 

 vation in this country a small pyramidal tree or bush densely 

 branched to the ground. Bark on young trees smooth, dull grey, 

 scaling off in small patches Uke a plane tree, changing to chalky- 

 white on old trunks by which the species can be recognized from 

 a long distance. Young shoots smooth, without down, greyish 

 green. Winter buds spindle-shaped, nearly |- in. long, not resinous, 

 composed of reddish brown scales. Leaves in threes, rather 

 sparsely arranged on the branchlets, persisting 3-4 years, giving 

 off a turpentiny odour when bruised, dull green, rather rigid, 

 flattened, 2-3 in. long, margins finely toothed, apex sharply 

 pointed, faint stomatic lines on each surface ; resin canals marginal 

 and prominent ; sheath soon falling away. Cones soHtary or in 

 pairs, subterminal but often appearing lateral by the growth of 

 a summer shoot, globose or ovoid, 2-2| in. long, on short, stout 

 stalks ; scales terminated by a reflexed, triangular spine. Seed 

 with a short, loosely attached wing. 



P. Bungeana is most closely allied to P. Gerardiana, from 

 which it is distinguished by its smaller cones and stiff er leaves. 

 From other three-leaved pines it is separated by its smooth, 

 scahng bark, sparsely arranged fohage, pecuhar habit, and the 

 strong odour of its bruised leaves. 



Native of China, where it was first seen by Dr. Bunge near 

 Pekin in 1831. It has lately been found in the mountains of 

 Cent. China by Wilson, and is widely cultivated by the Chinese 

 in the vicinity of temples and cemeteries. 



1 Brown, Nelson Courtlandt : Forest Products, their Manufacture a)id Use, 

 29 (1919). 



