Fagus cliffortioides, Hook. f.
Hook. Ic. Pl., t. 673.
Black Birch of portions of Wellington, Canterbury, Otago, and Southland.
White Birch of Nelson, and in part of Otago and Southland.
Rarely distinguished by the woodman from Entire-leaved Beech.
The mountain beech bears a close resemblance to the entire-leaved beech in general appearance, although it never attains the extreme dimensions of that species. The leaves are pointed at the apex and rounded or cordate at the base, so that there is but little difficulty in distinguishing the two kinds.
In the North Island it is confined to the mountain ranges, and appears to attain its northern limit at Lake Waikare on the East Cape. It is most
abundant on the mountains of the South Island, often forming the sole constituent of the forest from 2,000 feet to the limits of arboreal vegetation at about 4,000 feet. It descends to the sea-level in Preservation Inlet.
In many districts the abruptness of the higher limit is strongly marked: on the St. Arnaud Range, as on others in the South Island, the upper limit forms a tolerably even line running for miles at a little below 4,000 feet.
On Mount Torlesse a few small detached specimens attain an elevation of 4,600 feet or thereabouts.
Except in special situations it rarely exceeds 40 feet in height, and even, at low elevations is frequently much smaller. At the highest levels it is little more than a shrub, often with prostrate stems, and if exposed to the full influence of the wind with the branches so densely set that it is possible to walk for long distances over the tops.
In deep narrow valleys at high elevations this species is sometimes not more than from 6 to 10 feet high, but retains the arboreal habit. At the same time the leaves are excessively reduced in size, densely crowded, and fruit is produced in abundance. At first sight this state presents the appearance of a distinct species, but a careful examination speedily dispels the idea.
On the other hand, isolated specimens growing in the open at below 3,000 feet, are often branched from the base, and form charming symmetrical specimens of great beauty. When dotted over a wide area they give a peculiar park-like character to the scene, and are peculiarly attractive.
This species resembles Fagus solandri in the leaves of the young plant being destitute of hairs on the lower surface, while full-grown specimens have the leaves clothed with a thick layer of appressed white hairs. The distichous arrangement of the leaves is a noteworthy character, although in old specimens it is often obscured.
The quality of the timber is much the same as that of entire-leaved beech, and like that species it exhibits a considerable amount of durability in certain cases, while in others it perishes within five or six years, as in sheep-yards at Lake Pearson.
In many districts it is of value as affording the only available timber, but it assumes far greater importance when viewed with regard to its influence on climate. In this respect it is not easy to overrate its importance: its restraining action in the prevention of floods in certain situations is so marked, that the destruction of the mountain beech forests would speedily bring about the devastation of large tracts of country at low levels.
In wet situations the timber of this species often proves durable. Mr. J. D. Enys informed me of an instance in which a large sleeper at the margin of a spring in a situation where it was constantly moist was sound
and good after being sixteen years in use. Some of the telegraph poles of the first line erected in the Waimakariri Country were furnished by this species; those fixed in dry soils perished in four or five years, while those driven in swamps remained sound for a much longer period. Similar results have been obtained with fencing posts furnished by mountain beech.