CHAP. CIV. BETULA'CEZ. A/LNUS. 1679 
species we think only varieties, as we have indicated by 
putting the letter g. in parentheses. 
Description. The alder, in a wild state, even in favour- 
able situations, is seldom seen higher than 40 ft. or 50 ft.; 
but in uncultivated grounds, and in good soil near water, Suc 
it will attain the height of 50 ft. or 60 ft., and upwards. 
This is not only the case with the species, but with the 
variety A. g. laciniata, which forms a handsome pyramidal 
tree; which, at Syon, has attained the height of 63 ft., 
and at Woburn Farm, near Chertsey, is still higher. The 
bark of the common alder, in oldish trees, is nearly black, 
and full of clefts; the colour of the wood is white before 
the tree is cut down; but, immediately on being cut, the 
surface of the wound becomes of a deep red; soon fading, 
however, into the pale flesh-colour, which the whole of 
the wood of this tree, when cut down, takes when dry, and 
retains ever afterwards. The wood is homogeneous, tender, 
and without much tenacity. The branches, when they 
are young, and the tree is in a state of vigorous growth, 
have a triangular form; but, when mature, they are round. The bark, at the 
rising of the sap, separates from the wood with very great facility. The 
leaves, when in the bud, are folded in the manner of a fan, very glutinous, 
and completely enclosed by two oblong 
stipules of a whitish green. They are from 
3in. to 4in. long, and nearly as broad. 
The petiole is about lin. long, and | ae 
longed on the disk of the leaf, in the form 
of a very prominent nerve on the under 
side, from which proceed to the right and 
left other prominent nerves, in each of the. 
axils formed by which is a little tuft of 
cottony hair. The characteristics of the 
leaves of this species, as compared with 
those of other species of the genus, and 
especially of A. incana, is, that they are 
always rounded at the summit, and never , 
Pees though this distinction does not ° 
old good when applied to some of the 
varieties, such as A. g. laciniata. The leaves are of a deep dark green; and both 
the young shoots and leaves are covered with a glutinous substance, more espe- 
cially in the early partof summer. The male catkins are cylindrical, like those 
of the birch, and appear in the autumn; while the female ones, which are on 
branched footstalks, are of a short conical form, like a small fir cone, and 
- are produced in spring along with the leaves. On Mount Caucasus, Pallas 
informs us, the female catkins come out about the end of February; but, in 
the north of Russia, in March and April. The rate of growth of the alder, 
in a favourable soil and situation, is about 2ft. or 3ft. a year for four or 
five years; so that a tree 10 years pianted will frequently attain the height of 
20 ft. or 25ft.; and at 60 years the tree is supposed to have arrived at 
maturity. The roots are creeping; and sometimes, but rarely, they throw 
up suckers. The shade and fallen leaves of this tree are not injurious 
to grass. 
Geography, History, §c. The common alder is the most aquatic of Euro- 
pean trees, being found in wet swampy grounds, throughout the whole of 
Europe, in situations too moist for even the willow and the poplar. In 
meadows, and by river sides in the plains, it becomes a considerable tree; but 
on mountains,’and in the most northerly parts of Sweden, it diminishes to a 
shrub. It is found in the west, east, and north of Asi andin the north of 
5R 
