Bram.—0On the Building Materials of Otago. 169 
9rd. Section of tree that has been felled in the West Taieri Bush 
for four years, 
All of which are still quite sound and fresh. 
No. 11. Black Heart Birch—Fagus solandri and F. cliffortioides. Dr. 
Hooker says that although very similar these plants are distinct species, 
but the only difference he makes is in the shape of the leaf. Mr Kirk, in a 
note to me, says, ** I do not know Fagus cliffortioides apart from F. solandri.” 
We may therefore assume that they are identical, at least so far as their 
economic value is concerned. 
Black heart birch is found in the same forest as the other two, but is 
particularly plentiful on the west coast. There is also a considerable 
quantity at the Blue Mountains in the Pomahaka district. In size this 
tree occupies an intermediate place between the red and silver birches. It 
grows to a height of from seventy to one hundred feet, with a straight, clear 
trunk fifty to eighty feet long, and two feet six inches to five feet diameter. 
Two trees lately measured at Tuapeka Mouth were respectively seventy-two 
and seventy-four feet from the butt to the lowest branches. Two logs from 
the Blue Mountains, now lying near Stirling, measure respectively forty- 
seven feet long by two feet two inches in diameter, and thirty-four feet long 
by three feet nine inches in diameter. They are both quite straight and 
cylindrical, and without crack or other flaw from end to end. The trunks 
from which these logs were cut measured fifty or sixty feet, but there are 
many in the same bush eighty feet high to the lowest branch. 
Judging from the annual rings, this is the fastest growing tree in Otago. 
A trunk three feet in diameter is estimated to be 150 years old. In some 
cases there are only three or four rings in an inch, which shows it to be a 
growth almost equal to that of oak, elm, or beech, the fastest growing 
English trees. Black heart bitch grows well under cultivation. There 
are a number of healthy young plants in private gardens in Dunedin. So 
far as I can ascertain, this tree is not subject to heart-shake or decay. 
Black heart birch has, when young, a thin smooth bark of a light grey 
colour, like kamai, and quite free of the horizontal markings that occur in 
silver birch. It gets darker, rougher, and thicker with age like the latter, 
but never attains to the thickness or roughness of the red birch bark. The 
leaf of this tree is easily distinguished. It is of an oval or pear shape from 
one-quarter to seven-eighths of an inch in length, and entire on the edge. 
The size of the leaf does not change with the growth of the tree, but the 
same forest produees allsizes. The largest and smallest specimens I have 
seen are both from Five Rivers. 
The wood of the black heart birch is quite different from that of its two 
congeners, It is of a grey or yellowish ground colour, with dark streaks, 
v 
