PINACE^ 357 



glabrous, with rounded, entire or irregularly toothed margins. 



Frequent on the mountains of N.E. Hupeh, China, between 

 4,800-7,500 ft. altitude, and also occurring in N.W. Szechuen. 



Young plants in collections differ from all the other Chinese 

 spruces in cultivation by their very narrow, dark shining green, 

 sharp-pointed leaves. 



PL Wils. ii, 27 (1914). 



PINUS, Linn^us. 



Pines. 



The true pines are evergreen resin-yielding trees, belonging 

 to the tribe Abietinece and widely distributed in the northern 

 hemisphere from the limit of tree growth on the plains of N. 

 Europe, Asia, and N. America, to the sub-tropical regions of N. 

 Africa, the Canary Islands, Asia Minor, Burma, the Philippine 

 Islands, Central America, Florida, the Bahamas, and British 

 Honduras. In tropical countries they are usually found at sub- 

 tropical or warm temperate altitudes, rarely on the plains. 



Young to middle-aged trees are usually of pyramidal habit with 

 horizontal branches disposed in regular whorls, but mature trees 

 may have flat, round, or spreading crowns. The trunks of isolated 

 trees are usually large at the base and taper rapidly as they 

 advance in height, the lower branches being retained throughout 

 life. Forest-grown trees lose their lower branches early and mature 

 with long, clean, columnar trunks with Uttle taper but smaller at 

 the base than those of isolated specimens. In a few species the 

 production of more than one leading shoot is fairly common. 



Bark usually thick, rough, and deeply furrowed, but in some 

 species thin and scaly. The long shoots produced in spring either 

 form a single internode ^ consisting of (a) a leafless base which 

 often bears the staminate flowers, (b) a longer upper portion 

 bearing foliage and ending in a terminal bud surrounded by a 

 whorl of smaller buds, one or more of which may be replaced by 

 pistillate flowers (young cones), or the long shoot consists of two, 

 or rarely more, internodes,^ each with a leafless base, a leaf- 

 bearing portion, and a whorl of buds. Some species are liable to 

 produce occasional shoots bearing juvenile leaves until advanced 

 in age. Such shoots often appear from adventitious buds. The 

 terminal buds vary in character in different species as regards 

 the shape and character of their scales, which may be resinous 

 or non-resinous. 



Leaves of three kinds : (a) Primordial leaves borne on seedling 

 plants, solitary, spirally arranged, linear lanceolate, and toothed ; 

 (6) Scale leaves bearing in their axils the short shoots, triangular 



1 Termed uninodal pines by Shaw, Genus Pinus. 

 ^ Multinodal pines of Shaw. 



