CONIFERS 39 



cylindrical pendant cone, crowded on the upper branches or in some species scattered 

 over the upper half of the tree. Seeds ovoid or oblong, usually acute at the base, 

 much shorter than their wings ; outer seed-coat crustaceous, light or dark brown, the 

 inner membranaceous, pale chestnut-brown ; cotyledons 4-15. 



Picea is widely distributed through the colder and temperate regions of the north- 

 ern hemisphere, some species forming great forests on plains and high mountain 

 slopes. Eighteen species are now recognized, ranging from the Arctic Circle to the 

 slopes of the southern Appalachian Mountains and to those of northern New Mexico 

 and Arizona in the New World, and to central and southeastern Europe, the Caucasus, 

 the Himalayas, western China and Japan. Of exotic species the so-called Norway 

 Spruce, Picea Abies, Karst., one of the most valuable timber-trees of Europe, has 

 been largely planted for ornament and shelter in the eastern states, where the Cau- 

 casian Picea orientalis, Carr., and some of the Japanese species also flourish. 



Picea was probably the classical name of the Spruce-tree. 



CONSPECTUS OF THE NORTH AMERICAN SPECIES. 



Leaves 4-sided, with stomata on the 4 sides. 

 Cone-scales rounded at the apex. 



Cone-scales stiff and rigid at maturity ; branchlets pubescent. 



Cones ovate on strongly incurved stalks, persistent for many years, their scales erose 



or dentate ; leaves blue-green. 1. P. Mariana (A B, F). 



Cones ovate-oblong, early deciduous, their scales entire or denticulate ; leaves dark 



yellow-green. 2. P. rubens (A). 



Cone-scales soft and flexible at maturity ; branchlets glabrous. 



Cones oblong-cylindrical, slender, their scales entire ; leaves blue-green. 



3. P. Canadensis (A B, F). 



Cone-scales oblong or rhomboidal, narrowed to the truncate or acute apex ; leaves blue- 

 green. 



Cones oblong-cylindrical or oval ; branchlets pubescent ; leaves soft and flexible. 



4. P. Engelmanni (F, B, G). 

 Cones oblong-cylindrical ; branchlets glabrous ; leaves rigid, spinescent. 



5. P. Parryana (F). 



Leaves flattened, usually with stomata only on the upper surface. 

 Cone-scales rounded, entire ; branchlets pubescent. 



Cones oblong-cylindrical, leaves obtuse, with stomata only on the upper surface. 



6. P. Breweriana (G). 



Cone-scales oblong-oval, rounded, denticulate above the middle ; branchlets glabrous. 

 Cones cylindrical-ovoid, leaves acute or acuminate, with stomata occasionally on the 

 lower surface. 7. P. Sitchensis (B, G). 



1. Leaves 4-sided. 



* Cone-scales rounded at the apex. 

 -^Branchlets pubescent. 



1. Picea Mariana, B., S. & P. Black Spruce. 



Leaves slightly incurved above the middle, abruptly contracted at the apex into 

 short callous tips, pale blue-green and glaucous at maturity, -J-'-f ' l"g hoary on 

 the upper surface from the broad bands of stomata, and lustrous and slightly stoma- 

 tiferous on the lower surface. Flowers : staminate subglobose, with dark red 

 anthers ; pistillate oblong-cylindrical, with obovate purple scales rounded above, and 

 oblong purple glaucous bracts rounded and denticulate at the apex. Fruit ovate, 





