248 BOTANY. 



and tree-ferns. They are of slow growth and are long- 

 lived; the stem elongates by a slowly unfolding terminal 

 bud, which gives rise to a crown of widely spreading pin- 

 nate leaves, which are constantly renewed above as they die 

 and fall away below. About eighty-three species are now 

 known, all confined to tropical or sub-tropical climates. 

 In geological times (Triassic and Jurassic) they were very 

 abundant. 



465. The Conifers (Order 37, Costifbr^) are mostly 

 trees of a considerable size, with branching, spreading, or 

 spiry tops, as the pines, spruces, firs, etc., etc. They are 

 generally of rapid growth, and in many cases attain a great 

 height and diameter. In the greater number of species 

 the leaves are persistent, and the trees, consequently, ever- 

 green. 



466. The order contains two families, viz., Taxacese 

 and Pinaceas, including about three hundred species, which 

 are distributed mainly in the cooler climates of the globe. 

 Mnety or more species occur in North America, and con- 

 stitute in many places enormous forests hundreds of miles 

 in extent. 



The pines (Pinus) include tte most important trees of the order. 

 The White pine (P. strobus), formerly very abundant from the Great 

 Lakes eastward, furnishes the greater part of the " pine lumber" so 

 largely used in the Northern States for building and other purposes. 

 The Sugar-pine (P. lambertiana) of California resembles the White 

 pine, but is much larger, being often 60 to 90 metres (300 to 300 feet) 

 in height, with a trunk 3 to 6 metres (10 to 20 feet) in diameter. 

 The Southern pine (P. palustris), abundant from the Carolinas to 

 Texas, is a tree of moderate dimensions, whose hard wood is " supe- 

 rior to that of any other North American pine," and is known in the 

 markets as Yellow or Georgia pine. Scotch pine (P. sylvestris) and 

 Austrian pine (P. laricio), both natives of Europe, are extensively 

 planted in this country. Besides the spruces, firs, larches, cedars, 

 and many other well-known trees, the order contains the two species 

 of great Redwoods. The most remarkable is called the Big Tree 



