1 86 BOTANY. 



305, General aspect of the white pine, The white pine 

 (Pinus strobus) is found in the Eastern United States. In 

 favorable situations in the forest it reaches a height of about 50 

 meters (about 160 feet), and the trunk a diameter of ovei 

 I meter. In well-formed trees the trunk is straight and tower- 

 ing; the branches where the sunlight has access and the trees 

 are not crowded, or are young, reaching out in graceful arms, 

 form a pyramidal outline to the tree. In old and dense forests 

 the lower branches, because of lack of sunlight, have died away, 

 leaving tall, bare trunks for a considerable height. 



306, The long shoots of the pine. The branches are of two 

 kinds. Those which we readily recognize are the long 

 branches, so called because the growth in length each year is 

 considerable. The terminal bud of the long branches, as well 

 as of the main stem, continues each year the growth of the 

 main branch or shoot; while the lateral long branches arise 

 each year from buds which are crowded close together around 

 the base of the terminal bud. The lateral long branches of each 

 year thus appear to be in a whorl. The distance between each 

 false whorl of branches, then, represents one year's growth in 

 length of the main stem or long branch. 



307. The dwarf shoots of the pine. The dwarf branches are 

 all lateral on the long branches, or shoots. They are scattered 

 over the year's growth, and each bears a cluster of five long, 

 needle-shaped, green leaves, which remain on the tree for 

 several years. At the base of the green leaves are a number of 

 chaff-like scales, the previous bud scales. While the dwarf 

 branches thus bear green leaves, and scales, the long branches 

 bear only thin scale-like leaves which are not green. 



308. Spore-bearing leaves of the pine. The two kinds of' 

 spore-bearing leaves of the pine, and their close relatives, are so 

 different from anything which we have yet studied, and are so 

 unlike the green leaves of the pine, that we would scarcely 

 recognize them as belonging to this category. Indeed there is 

 great uncertainty regarding their origin. 



