TREES OF NORTH AMERICA 



Scales of the Lmale flj-wers numerous, spirally arranged, forming a woody cone; ovules 

 erect, 2 or many under each scale; leaves linear, alternate, often of 2 forms (decidu- 

 ous in Taxodiurri). TAXODI.E. 



Ovules and seeds numerous under each scale. 7. Sequoia. 



Ovules and seeds 2 under each scale ; leaves mostly spreading in 2 ranks. 8. Taxodium, 



Scales of the female flower few, decussate, forming a small cone, or rarely a berry; ovules 



2 or many under each scale; leaves decussate or in 3 ranks, often of 2 forms, usually 



scale-like, mostly adnate to the branch, the earliest free and subulate. CUPRESSINE.E. 



Fruit a cone; leaves scale-like. 



Cones oblong, their scales oblong, imbricated or valvate; seeds 2 under each scale, 



maturing the first year. 

 Scales of the cone 6, the middle ones only fertile; seeds unequally 2-winged. 



9. Libocedrus. 



Scales of the cone 8-12; seeds equally 2-winged. 10. Thuja. 



Cones subglobose, the scales peltate, maturing in one or two years; seeds few or 



many under each scale. 



Fruit maturing in two seasons; seeds many under each scale; branchlets terete or 

 4-winged. 11. Cupressus. 



Fruit maturing in one season; seeds 2 under each scale; branchlets flattened. 



12. Chamaecyparis. 



Fruit a berry formed by the coalition of the scales of the flower; ovules in pairs or 

 solitary; flowers dioecious; leaves decussate or in 3's, subulate or scale-like, often of 

 2 forms. 13. Juniperus. 



1. PINUS Duham. Pine. 



Trees or rarely shrubs, with deeply furrowed and sometimes laminate or with thin 

 and scaly bark, hard or often soft heartwood often conspicuously marked by dark bands 

 of summer cells impregnated with resin, pale nearly white sapwood 5 and large branch- 

 buds formed during summer and composed of minute buds in the axils of bud-scales, 

 becoming the bracts of the spring shoot. Leaves needle-shaped, clustered, the clusters 

 borne on deciduous spurs in the axils of scale-like primary leaves, inclosed in the bud 

 by numerous scales lengthening and forming a more or less persistent sheath at the base 

 of each cluster. Male flowers clustered at the base of leafy growing shoots of the year, 

 each flower surrounded at the base by an. involucre of 3-6 scalelike bracts, composed 

 of numerous sessile anthers, imbricated in many ranks and surmounted by crest-like 

 nearly orbicular connectives; the female subterminal or lateral, their scales in the axils of 

 non-accrescent bracts. Fruit a woody cone maturing at the end of the second or rarely 

 of the third season, composed of the hardened and woody scales of the flower more or 

 less thickened on the exposed surface (the apophysis), with the ends of the growth of the pre- 

 vious year appearing as terminal or dorsal brown protuberances or scars (the urnbo) . Seeds 

 usually obovoid, shorter or longer than their wings or rarely wingless; outer seed-coat 

 crustaceous or thick, hard, and bony, the inner membranaceous; cotyledons 3-18, usually 

 much shorter than the inferior radicle. 



Pinus is widely distributed through the northern hemisphere from the Arctic Circle 

 to the West Indies, the mountains of Central America, the Canary Islands, northern 

 Africa, the Philippine Islands, and Sumatra. About sixty-six species are recognized. Of 

 exotic species the so-called Scotch Pine, Pinus sylvestris L., of Europe and Asia, the Swiss 

 Stone Pine, Pinus cembra L., and the Austrian Pine and other forms of Pinus nigra 

 Arnold, from central and southern Europe, are often planted in the northeastern states, 

 and Pinus Pinaster Ait., of the coast region of western France and the Mediterranean 

 Basin is successfully cultivated in central and southern California. Pinus is the classical 

 name of the Pine-tree. 



The North American species can be conveniently grouped in two sections, Soft Pines 

 and Pitch Pines. 



