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C—ll

(h.) The Subalptne Scrub. On the west and south of Kuapehu, between the upper forest and the steppe, there is a more or less continuous belt of shrub:- or even low trees such as is usually encountered on a New Zealand mountain, many of the constituents descending into the upper forest, the two formations merging gradually into one another. The following is from notes taken at 3,700 ft. on the southern slopes of Ruapehu : "The association consists of stunted mountain-beech {Nothofagut cliffortioidet) 20 ft. tall, and the following: Phyllocladut alpinut, Dacrydium biforme, I). Bidwillii, Coprotma cuneata, Nothopaiur.i Colenioi, ('. fottidissima, Myrtut peduncvlata, Nothopanax simplex, Qritelinia littoralit, Astelia montana, a little Veronica lαvis, Gleichenia Cunninghatnii, Blechmtm flurmti/r, Sit/plielia fascieulata (this as a prostrate plant), Podocarpus nivalis, Qahnia pauciflora, Styphelia aeerota (as a carpet plant), small Libocedrus Bidwillii, The ground is carpeted with moss and the umbrella fern, the Astelia, the Gahnia, and seedlings growing through." "Approaching the outskirts, the beech gets much lower —say, 12 ft. tall, more or less." Also, patches of scrub appear on the steppe which succeeds it, portions of this latter formation or of semi-bog penetrating into the final scrubbelt, and form ing open patches of ground of considerable size. So far as the east of the volcanoes is concerned, there is no continuous zonal arrangement of the formations. Altitude certainly affects distribution, but the associations are governed chiefly liy the nature of the ground, its slope, and its exposure to wind and sun. Thus both forest and scrub do not form belts, but simply patches in favourable positions. The scrub usually occurs in the shelter of river-gullies. " wash-outs," or ridges. Disintegrated lava-Hows, where the stones are in large blocks, also afford shelter to a shrubby growth. Frequently the scrub extends over th*e river-bank out on to the original flood-plain. Generally speaking, the formation under consideration has nothing like the denseness of typical New Zealand subalpine scrub (Cockayne, 6). The shrubs touch, it is true, and there are « where on rocky slopes the rigid stems and branches point downwards, making an obstruction of a more typical kind for the explorer. Subalpine scrub is an advanced phase of shrub steppe : the shrubs are much the same, but they are taller, and arranged as a closed formation, whereas the latter is an open one. Also, much more Veronica lavis and Seneeio Bidwillii enter in, while Phyttocladus is extremely abundant (Photo. No. 26). Owing to the varied hues of the shrubs the formation has no uniformity of colour. The bright green of the Veronica contrasts with the paler green of other plants, and with the brown or reddish hue of the Dracophyllums. The chief plants of the eastern scrub are Veronica hn-ix, Dracophyllum Urvilleanum var. montanum, I), tubulatum, Pimelea buxifolia, PhyUocladus alpinut, Olearia nummularifolia, Seneeio Bidwillii, Nothopanax Colensoi, Veronica tetragona, Dacrydium Bidwillii, Pittosporiim rigidum South Island var., Catsinia VauviUier&ii, Dracophyllum recurvum, Aristotelia fruticosa. Another phase of subalpine scrub which might almost- be classed as forest is not uncommon here and there. Phyllocladut "//li/mx, with its very pale whitish-green "leaves," is dominant and in places almost pure. Then , is plenty of Dacrydium Bidwillii, no longer prostrate, but a small tree, with many stems each half a foot thick or so. Nothopnuax Colensoi and .V. simplex are also frequent. In short, the above is rather the beech-forest undergrowth without beech-trees, growing luxuriantly, than a kind of scrub. The plants grow very closely, and this and the Rtrong and stiff stems and branches makes the formation almost impenetrable. On Tongariro dense subalpine scrub is abundant in the gullies between 4,000 ft. and 5,000 ft., Phyllocladut alpinut being dominant. Such scrub, if sheltered or on better soil, assumes larger proportions, the Phyllocladut becomes of tree-dimensions, Podocarpu.< Hallii enters in, and there is low forest such as before described. Where the scrub is lowest Dracophyllum Urvilleanum var. montanum may be dominant. The formation will present a fairly even surface: the physiognomy is dependent also on the green of the two species of Nothopanax, the glaucous hue of Phyttocladut, and tin' erect habit of the Dracophyllum, here light green rather than brown. In such scrub there are the following species: Dracophyllum Urvilleanum var. montanum, Phyllocladut alpinus, Nothopanax Colensoi, N. simplex, N. Sinclairii, Griselinia littoralit, Olearia nummularifolia, t'i>ri<iriti thymifolia, Coprotma cuneata, C. fatidistima, C. parvifiora, Leptotpermum teoparium, Gleichenia Cunninghatnii, 0. dicarpa. Where most exposed this formation gives place to shrubsteppe, which is not only distinguished by its more lowly growth, but by the brownish shrubs and the straw-coloured tussock. (/.) Shrubs of I!i\ eh-gum-hs. A< about an altitude of :?,000 ft. in such gullies as do not contain forest are close-growing associations of shrubs. Where driest will be Leptotpermvm ecoparivm and /.. rricoides; but where more shady conditions prevail, then there is Pittosporiim Colensoi, Veronica salirifolia, Ariindn eonspieua, Olearia nitida, Griselinia littoralit, Nothopanax arboreum, N. Colensoi, Pseudopanax eratsifolium, Phormium tenam, or /'. Cookianum. (D.) STREAMS, BOGS, AND WET GROUND. (n.) Vegetation of Rmraiwo Water. The rivers issuing from the volcanic ranges are altogether too rapid for the higher plants, and are populated merely by a few algae, which are either submerged or mark on the boulders the average level of the stream. Those torrents which issue directly from solid-looking lava-flows are at first wide and pond-like (Photo. No. 28), and, although running rapidly enough, spread out and are shallow at their sides, wetting, too, the adjacent ground and making boggy conditions. In suchi, M'ontia fontana forms beautiful bright-green oushions (Photo. N'o. 27), and. where shallower,ltanunculut rivularis forms a close growth, spreading out on to the constantly wet silt. With it is mixed Moulin, Jiniciis nova-zelandxa, and a small-leaved and short-stalked form of Epilobium pedun-