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C—ll

Phyllocladus alpinus, its leaf-like shoots of a somewhat glaucous colour. This latter may assume a pyramidal form, 8 ft. or so tall, or be merely of a straggling habit and sparingly branched. There are also fairly dense bushes of Suttonia divaricata, Coprosma cuueata, Aristotelia fruticosa, C. parviflora, and V. microcarpa. These shrubs may grow so closely and be themselves so dense as to exclude the floor-vegetation. The second layer or tier of plants is made up of those more lowly ones which carpet the ground, and of the seedlings, ferns, and herbaceous plants —these frequently of considerable size—which grow through this covering or are clotted here and there. The most conspicuous of the mat-forming plants is the bright-green or occasionally dark-green filmy fern HymenophyUum multifidum, whose fronds arc sometimes BO much curled up that the plant looks dead. Both stoloniferous and matforming i.s Lagenophora petiolata, the small roundish leaves close to the ground, and the little, white, daisy-like flower-heads raised on straight slender stalks. A moss builds up low cushionlike masses of yellowish green, through which grow in abundance the beech seedlings; also the green, grass-like, narrow leaves and slender culms of Uncinia cosspitosa covering considerable areas, thanks to its creeping stems, which also benefit by the mossy covering. The broaderleaved and taller Uncinia australis is less common, and likes the more shady gullies and recesses. The small fern Blechnum penna marina is often quite common, and the club-moss Lycopodium fastigiatum, here erect and green, and not depressed and orange-coloured as on the steppe, may form spreading colonies. Seedlings of all the forest-plants are present, but the most common, next to those of the beech, are the cut-leaved form of Nothopanax simplex and Aristotelia fruticosa. Where the forest is' more open the piripiri (Acasna Sanguisorbce) is abundant. Near the outer rim of the formation is quite frequently a prostrate form of Styphelia acerosa, very different from the typical erect, dense-growing shrub, its wiry stems creeping through the loose layer of humus, and finally rising up for a few inches or even a foot. Other constituents of the forest, though not common, are Erechtites glabrescens, Nertera dichondrcefolia, J'ittosporum rigidum, Gaxtrodia Cunningham-it, and Myototit Forsteri. The gullies have a richer undergrowth than the slopes, and in such the dark-green, rather tall fern Polyttichum vcstitum and the delicate bright-green fronds of Hypolepis millefolium are abundant, while HymenophyUum multifidum is everywhere. Here, too, is a good deal of Astelia montana, with its arching, coriaceous, hairy, sword-like leaves, while in many places are fine colonies of the enormous moss, a foot or more tall, Polytrichum dendroidet. The forest-floor is fairly level. There are no roots spreading over the ground, nor the unevennesses these occasion in the hygrophytic forests. The ground, mossy or covered with a thick layer of brown leaves, is springy to the tread. The higher epiphytes and lianes are quite wanting. HymenophyUum, multifidum is common on the tree-trunks, and so are mosses and lichens, as before mentioned. Dead trees still standing (Photo. No. 15) or lying prone, are a frequent feature, while, as staled previously, seedlings and saplings are in abundance. So, if there are no fires, or interference from those animals which feed on the trees and especially destroy the bark and the undergrowth, these subalpine forests will long remain in their pristine vigour. Seedlings of most of the trees and shrubs are plentiful, even in forests where but few of the adults are present in the locality. The most abundant of all are the cut-leaved Nothopanax simplex, Aristotelia fruticosa, the beech itself, Nothopanax Colensoi, and finally the various species of Coprosma. (3.) Affinities of the Formation. Pure Nothofagus cliffortioidet forest is very common in certain parts of the South Island, especially the central Southern Adps mi their east side, but rarer in the North, where N. Mentietii is a mure abundant subalpine t?ee. The presence of the formation usually bespeaks a dry and poor soil and a small rainfall— i.e., for a mountain region and a high altitude. Probably powerful or frequent winds are a factor, too, which helps in determining its presence. Generally speaking, the forest we are considering has a richer undergrowth than the same formation in the eastern Southern Alps, but it is poorer in species as a whole, though this is a matter dependent on the history of the vegetation, and not on any special ecological factors. (e.) Subalpine Beech Fokest of Nothofagus Menziesii (Silver-beech). This formation occurs at approximately an altitude of between 3,200 ft. and 3,700 ft. on the south and west of Ruapehu. It is also found in the higher parts of some of the river-gorges to the east of Tongariro. N. Menziesii is altogether a larger tree than N. rliffortioides, and is frequently more than 70 ft. in height, with a trunk 3 ft. in diameter. The tree itself is by no means confined to the subalpine zone, but occurs in abundance mixed with N. fusca at as low as 2,000 ft. altitude, even descending still lower into the mixed taxad forest. The forest zones, as already noted, are only well defined in their central parts; elsewhere there is a combination of the two most adjacent. At about 3,400 ft. the trees are 40 ft. or 50 ft. tall, and consist almost entirely of N. Menziesii, though at a higher altitude than this a good deal of N. fusca is still present in places. The N. Menziesii forest of this district owes its physiognomy in part to the short leafy boughs or twigs which are given off from the trunks almost to their bases, while the abundance of Coprosma fcetidissima, which here replaces C. tenuifolia of the N. fusca forest, gives the stamp to the straggling and rather open undergrowth. Some of the trees are 2 ft. in diameter, but many are much less, and the thick ones are distant, being merely dotted here and there. The smaller trees and the thicker-stemmed shrubs are covered much more abundantly with mosses than are those in the mountain-beech forest. All the plants of this latter forest are also present here, but in addition are the following: Luzuriaga parvi flora, Libertin pulchella. Alseuosmia macrophyUa, Coprosma tenuifolia, Uncinia leptostachi/a, Gahnia pauci-