78 FOEEST TEEES OF THE PACIFIC SLOPE. 



central column. They never fall away until the cone is rotted to pieces. Two 

 seeds are borne under each cone scale. The seeds are light and are provided at 

 one end with a thin wing which enables the wind to disseminate them widely. 

 Seed-leaves, sometimes 4, but commonly from 5 to about 15. 



The spruces are exceedingly important forest trees. They yield superior 

 saw-timber and the even-grained wood can be used for a great many purposes. 

 For paper pulp the wood of these trees is unsurpassed by any other. Seven 

 species are indigenous to North America, all of which are abundantly, or 

 exclusively, represented in the United States. Four are distributed over the 

 western half of the United States, and three range mainly through north- 

 eastern United States and Canada, while two of these extend, almost entirely 

 in Canada from the Great Lake region, into Alaska. 



Engelmann Spruce. 

 Picea engelmanni Engelmann.a 



DISTINGUISHING CHARACTERISTICS. 



In dense stands Engelmann spruce has a straight, clean trunk with a close, 

 very short, narrowly pyramidal crown of small branches ; the upper part of the 

 crown has exceedingly short sprays, forming a narrow spire. Such trees are 

 from 80 to 100 feet or more in height, and from 18 to 36 inches in diameter. 

 Larger trees occur sometimes. Singly, or in an open stand, it forms a similar 

 but longer crown, with drooping lower branches which may extend down to the 

 ground. Such trees are usually from 60 to 80 feet high with very tapering 

 trunks, and if exposed to heavy winds, the lower branches are often long and 

 stout. From all of the main horizontal branches hang numerous tassel-like 

 side branchlets which give the tree a very compact appearance. At high altitudes 

 it is often not more than 2 or 4 feet high. A spike-like stem bears a few sbort 

 densely-leaved branchlets while enormously long branches spread over the 

 ground from the base of the trunk. The foliage is a deep blue-green, on some 

 trees with a decidedly silvery or whitish tinge. This silvery tinge is very 

 marked on young trees ; occasionally, however, large and moderately old trees 

 still retain it. The bark becomes scaly even on rather young trees. On 

 maturer trunks it is thin, dark purplish-brown or russet-red, and outwardly 

 composed of very loosely attached small scales. The 4-angled leaves (fig. 29) 

 are soft to the touch, usually about an inch in length, but often longer, and are 

 spreading on young branchlets (fig. 29) which do not bear cones, while on cone- 

 bearing twigs they are commonly crowded and of a shorter type; they are often 

 crowded and curved so as to appear mainly on the upper part of the branchlet 

 The point of the leaf is characteristically short and flat ; short leaves exhibit 

 this more strongly than do the longer ones. A cross-section of the leaf shows no 

 resin ducts. A disagreeable odor is emitted by leaves and young shoots when 

 crushed. Young shoots are more or less minutely hairy and may remain so for 

 about three years. The cones, which mature in a single season, are ripe by the 

 middle or latter part of August. Most of them are borne near the top of the 

 crown. By October the seed is usually all shed. Cones (fig. 29) vary greatly 



" Dr. George Engelmann did not name this tree in honor of himself. Parry (Trans. 

 Acad. Sci. St. Louis, II, 122, 1863) recognizing that the tree had been referred by Engel- 

 mann to Abies nigra (another species), called it Abies Engelmanni, which proved to be a 

 nomen nudum. Later Engelmann (loc. cit., 212) cited Parry's name, and in doing this 

 formed a new name, Picea engelmanni, which he credited to Parry. As a matter of fact, 

 Parry did not write Picea engelmanni, consequently Engelmann was the first publisher of 

 Picea engelmanni, but certainly not with a knowledge that he must be cited as its author. 



