26 BL'LLETIX 299, 17. S. DEPAETMEXT OF AGEICULTTTBE. 
the open, diameter growth is more rapid, but the tree develops only 
a very short trunk and large, wide-spreading lateral branches, and is 
very much inclined to fork, all at the expense of growth in height, and 
of length, clearness, and cylindricity of bole. Unfavorable sites 
make themselves at once apparent in a lower rate of height growth 
in do min ant trees. The boles are shorter, more apt to be crooked, 
and more branchy. In mixed natural stands on such sites ash is 
usually a spindling, overtopped tree. 
In original forests, ashes from 200 to 300 years old, 3 to 5 feet in 
diameter, and from 125 to 175 feet in height were formerly common, 
but now 3 feet in diameter is exceedingly large. TVhite ash attains 
greater height than black or green ash. but is surpassed in diameter 
and age by black ash. Green ash grows larger in diameter than white 
ash. but does not become so tall nor live so long. 
Crowns of dominant ash trees growing in the forest occupy usually 
one-third to hah the total height of the tree, more on young trees and 
less on old trees. During the period of rapid height growth, which 
continues till the tree is from 40 to 60 years old. the crown is rather 
narrow in proportion to its length and more or less cone shaped: as 
its age increases it broadens out and becomes dome shaped, and in 
old age comparatively flat. In youth the crown is considerably 
longer than it is wide, but this changes with age until the width is 
greater than the length. Trees crowded on the sides have short, 
oppressed crowns, often occupying less than a quarter of the total 
height. (PL VIII. fig. 2.) 
Ash. because of its intolerance, prunes itself readily when growing 
in the forest, and develops long, clear, straight boles commonly free 
of branches for half its total height. The boles have usually a com- 
paratively rapid taper (Tables 25 to 29) . Ash trees which have grown 
under very crowded conditions often have clear lengths of two-thirds 
or more of their total height. 
The species vary somewhat in their characteristic forms as a 
result of their relative tolerance. Blue (PL IX. fig. 1), black, and 
water ashes have the most persistent limbs and- the shortest clear 
lengths, develop "water sprouts'' under lesser light conditions, and 
for this reason are less desirable to grow (on good sites at least) than 
white, Biltmore, green, and red ashes. 
