The Subalpine Scrub.

In many places on the high mountains in New Zealand, especially in a part where the rainfall is excessive, upon emerging from the upper forest one is confronted with a formidable natural fence, many chains in breadth, dividing the forest from the meadow land. On certain mountains this belt is absent, or represented by stunted beechtrees or isolated patches of shrubs. The above barrier, composed of a thick and varied growth of shrubs, is designated the "subalpine scrub," and if unprovided with a. track is virtually impenetrable (fig. 21). The shrubs, dense in themselves, have such wiry or rigid branches interlacing into one another that no passage can be made between them. In many places where it is impossible to crawl on one's hands and knees beneath the close mass, the only alternative is to walk upon the top.

Fig. 21.—Exterior of Subalpine Serub of Mount Anglem, Stewart Island. The large-leaved shrub is Olearia Colensoi; the shrub with erect branches raised slightly above the general level is Dracophyllum longifolium.
Lands Department.] [Photo, F. G. Gibbs.

At first sight it might seem that such plants would be worthless for garden purposes, and yet they are the very élite of the New Zealand flora. The scrubs of the montane and subalpine river-beds and terraces may also be included here.

These scrubs are the headquarters of the shrubby speedwells (Veronica).Here is Veronica cupressoides, named most fittingly, for no one seeing it for the first time and out of bloom could dream it was not a cypress. Other veronicas met with are — V. buxifolia var. odora, forming shining green bushes, round as a cricket-ball;

Fig. 22.—Olearia macrodonta (probably).
[Photo, J. Crosby Smith.

V. Traversii, which is of similar habit, but with much less glossy foliage; V. glaucophylla, with sage-green leaves; V. subalpina, an early-blooming species; V. monticola; V. vernicosa: and, indeed, there are dozens of species, many of which strongly resemble one another.

Daisy-shrubs (Olearia) are much in evidence. Common are— O. ilicifolia (the native holly), with musk-scented prickly crinkled leaves; O. macrodonta, somewhat like the above, but with broader and greener leaves (fig. 22); O. nummularifolia (fig. 23), with small page 58

Fig. 23.—Olearia nummularifolia. Subalpine Scrub of Mount Ruapehu.
Lands Department.] [Photo, L. Cockayne.

page 59hard and leathery leaves; O. cymbifolia, similar to the last-mentioned, but with the margins of the leaves much recurved; O. moschata, after the manner of O. nummularifolia, but with larger and paler-coloured leaves; O. nitida, with rather large, glossy leaves, covered on the under-surface with a shining mat of hairs; and O. Colensoi, with thick, rather large leaves, much toothed and covered beneath with a thick mat of white hairs. The remarkable O. lacunosa, with its leaves rather like those of a juvenile lancewood, and its relative O. excorticata, with broader and shorter leaves, are rarer, being confined to the Tararua Mountains in the North Island, and to the northwest and west of the South Island.

Other plants of the daisy family are the cassinias, C. Vauvilliersii and C. albida, this latter being confined to the Kaikoura and neighbouring mountains. To the same family belong also the shrubby groundsels, very common plants of the subalpine scrub, such as Senecio elaeagnifolius, S. Bidwillii, S. cassinioides, and S. Monroi.

The heaths are represented by various species of Dracophyllum and by Archeria Traversii and Gaultheria rupestris, the latter to be recognised by its lily-of-the-valley-like flowers, after the manner of those of G. oppositifolia of the central heath.

Dracophyllum Traversii is a magnificent small tree, with smooth, naked, brown stems, crowned at their extremities with rosettes of stiff, reddish leaves, having long-drawn-out points arching downwards. The subalpine flax (Phormium Cookianum), also a plant of sea-cliffs, is common, as is also, in some localities, one of the speargrasses (Aciphylla Colensoi, var. maxima), a most formidable plant with bayonet-like leaves a yard long.

Little can be said here regarding the adaptations of the members of this society. Like subalpine plants the world over, their surroundings, notwithstanding an abundant rainfall, demand protection against drought. A dense, felt-like mass of hairs is frequently present on the under-surfaces of the leaves. Very leathery leaves are common, and these have a special internal structure to account for their leatheriness, which is of advantage to its possessors. Other adaptations similar to those found in the before-described heath plants are frequently present.