﻿Treefi of Neiu Yo7^k State 345 



Aside from a few shrubs they are all arborescent and world-wide 

 in distribution but with a preponderance of forms in the north 

 temperate zone. Certain species form almost pure stands of ever- 

 green forest which cover extensive tracts. 



Btids scaly. Leaves acicular, narrowly oblong, awl-shaped or scale-like, 

 parallel-veined, solitary or fascicled, generally persistent. Flowers usually 

 monoecious (dioecious in Juniperus), destitute of perianth, consisting of 

 groups of sporophylls which are arranged spirally or cyclic in catkin-liie 

 clusters and bear ovules or pollen sacs on their faces ; flowers usually sub- 

 tended by an involucre of enlarged bud-scales; scales of male cone bearing 

 2 anther sacs; scales of ovulate cones bearing 2 or more ovules on the inner 

 face. Fruit a woody or rarely a fleshy {Juniperus) cone consisting of indu- 

 rated or fleshy scales ; seeds often -winged, copiously albuminous ; embryo axile, 

 with 2 or more cotyledons. 



KEY TO THE GENERA page 



1. Leaves spirally arranged or borne in fascicles 2 



1. Leaves all opposite in pairs 6 



2. Leaves acicular, born in fascicles of 2-5 Pinus 3i5 



2. Leaves linear or filiform, fascicled or scattered 3 



3. Leaves fascicled on short spurs and scattered spirally on the growth of the 



season; foliage deciduous Larix 346 



3. Leaves spirally arranged; foliage persistent 4 



4. Leaves, 4-sided, harsh and prickly to the touch, not prominently white- 

 lined on the lower side Picea 347 



4. Leaves flattish, with soft feel, whitened along two prominent lines 



beneath 5 



5. Leaves jointed to persistent woody stalks; branchlets roughened by persistent 



leaf-bases Tsuga 347 



5. Leaves sessile, leaving round leaf-scars on falling; branchlets smooth 



Abies 3 IS 



6. Sprays flattened ; branchlets appearing in one plane 7 



6. Sprays not flattened ; branchlets spreading Juniperus 349 



7. Leaves of 2 sorts; young twigs prominently flattened Thuya 348 



7. Leaves all alike; young twigs not prominently flattened Chamaecyparis 349 



THE PINES. Genus PINUS (Tourn.) L. 

 The genus Pinus is represented by evergreen trees and a few 

 shrubs which are natives of the northern hemisphere and chiefly 

 of temperate regions. Many species are of great economic impor- 

 tance as timber trees and cover extensive tracts, often in nearly 

 pure stands. About eighty species are recognized of which thirty- 

 four are indigenous to the United States. Six species are found 

 within the boundaries of New York State. 



Leaves evergreen, acicular, in fascicles of 2-5 which are borne on rudimen- 

 tary branches in the axils of primary scale-leaves; fascicles arising from scaly 

 buds, the scales of which lengthen and form a more or less persistent sheath 

 at the base of the fascicle. Flowers vernal, monoecious; staminate flowers 

 clustered at the base of the growth of the season, each flower subtended by an 

 involucre of 3-6 scale-like bracts ; stamens numerous, spirally arranged and 



