SPRUCE AND BALSAM FIR TREES. 11 



Engelmami spruce was published in 18G3, since which time writers 

 on North American trees have generally agreed in maintaining the 

 different wild forms of this tree as one species. 



Three or four garden forms of this spruce have been designated 

 as varieties. 1 They are distinguished by their crown habit, size, or 

 the color and length of the leaves. 



DISTINGUISHING CHARACTERISTICS. 



In dense stands Engelmann spruce has a straight, clean, slightly 

 tapering trunk with a close, very short, narrowly pyramidal crown 

 of small branches; the upper-crown branches are exceedingly short 

 and form a narrow spirelike point. Such trees are from 80 to 100 

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

 trees occur sometimes, but they are now rather rare. When growing 

 singly or in an open stand, Engelmann spruce has a similarly shaped 

 but longer crown, with drooping lower branches often extending 

 down to the ground. The middle-crown branches are horizontal and 

 the top branches strongly upright. Trees of this form 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 branches hang numerous tassel-like side branchlets 

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

 Engelmann spruce is often not more than from 2 to 4 feet high, when 

 the spikelike stem bears only a few short, densely leaved branchlets, 

 while enormously long branches grow from the base of the stunted 

 trunk and spread over the ground. The trunk bark becomes scaly 

 even on rather young trees. On older and larger trees it is thin, dark 

 purplish-brown or russet-red, and outwardly composed of very loosely 

 attached small scales. 



The foliage of Engelmann spruce is a deep blue-green, that of 

 some trees . being decidedly silvery or whitish. This silvery or 

 whitish tinge is very marked on young trees, but occasionally large 

 and moderately old trees still retain it. The 4-angled leaves (PL 

 IV, c) are rather soft to the touch, usually about an inch in length, 

 but often longer, especially on young, vigorous trees. The leaves 

 are spreading on young twigs and on those which do not bear cones, 

 while on cone-bearing twigs (PL IV) they are commonly crowded 

 and usually shorter; they are also often curved so as to appear to 

 grow mainly on the upper side of the branchlet. The point of the 

 leaf is, as a rule, characteristically short and flattish, the short types 

 of leaves exhibiting this more strongly than the longer ones (PL 



1 Picea engelmanni griseifolia Sudw. (=" P. e. glauca"), P. e. argyrophylla Sudw. 

 (="P. e. argentea"), P. e. minutifolia Sudw. (==" P. c. microphylla Hesse"), and P. e. 

 fendleri Henry are the garden varieties found in cultivation. 



