Page:Transactions and Proceedings of the New Zealand Institute - Volume 1 (2nd ed.).djvu/193

This page has been proofread, but needs to be validated.
HectorGeographical Botany of New Zealand
159

limit of the forests. The most striking feature of this western bush is, however, the wonderful luxuriance of cryptogamic plants, every shrub and tree being loaded with damp lichens, mosses, and fungi, which rapidly destroy the timber.

A2.—The mixed bush of the East Coast presents a marked difference from that on the west: on the whole, the timber is better grown and of larger size, and there is a much greater variety of Pines. Its most characteristic development is around Dunedin, where it is rare to meet any Ironwood, Karmahi, or Birch, which are so common on the west, Black and White Birch being wholly wanting.

Zone B.—In crossing the alpine ranges to the eastern side, the upper limit of the forest is at a less elevation, reaching to only 3,500 feet, and along the eastern slope of the mountains consists nearly wholly of Birch trees, with patches of mixed bush in favourable situations by the sides of the larger lakes. The valleys in this district are generally occupied by a dense scrub, consisting of Veronicas, Cassinias, and Olearias, resembling somewhat the sub-alpine flora, while the woods are skirted by a luxuriant growth of the handsome Lace-bark tree (Plagianthus lyallii), with its delicate green leaves and large white flowers.

Zone C1.—As has been already observed, the influence of the mountains in intercepting moist westerly winds, has given to the district in the central part of the island a flora which possesses almost a continental or arid type.

Cryptogamic plants, which are generally so abundant in New Zealand, are almost wanting, being largely reduced in relative percentage to the phanerogamic flora.

The plains are covered with grasses, the roots of which are gathered into tufts or tussocks, intermixed with the Bayonet grass or “Wild Spaniard” (Aciphylla colensoi), Toumatakuru (Discaria toumatou), and a great variety of the New Zealand brooms (Carmichelia), with small Orchids, Pimelias, and ericaceous plants.

Advancing towards the east, the grasses acquire a different character, indicating the influence of moisture derived from the eastern sea-board.

The yellow tussock predominates, and is intermixed with a rank growth of fern (Pteris aquilina, var. esculenta), Tutu (Coriaria), several species, Flax (Phormium tenax), and the soft-leaved Spear-grass (Aciphylla squarrosa), all of which latter plants rarely occur in the interior or lake district.

Zone D1.—This is the zone of sub-alpine plants, which is especially distinguished by the prevalence of large bunches of Snow-grass, which term includes various species of Danthonia and Agrostis, intermixed with scrubby