3. Lower Tussock Meadow.
Buchanan writes (9, p, 398), “The whole coast-line is ragged in the extreme, although inland large flat areas may be seen apparently covered by grasses and indicating rich pasture. This appearance, however, on closer examination, is found to be deceptive, as but few grasses exist, and a coarse wet cyperaceous pasture prevails, which would prove worthless for feed except fox cattle of a hardy breed that would stand the rigours of the climate. There is no doubt, however, that on the lower levels, where soil can accumulate, a rich though coarse vegetation exists; but the land is so spongy and wet that the finer grasses cannot thrive. The extreme wetness of the soil is shown by the fact that wherever a plant is dug out with a knife the hole immediately fills with water, and an indication is thus obtained of the treatment such plants should receive when it is attempted to grow them in a drier climate.”
However true the above may be as regards certain portions of the island, it certainly does not in the least apply to the parts visited by me, and extending from sea-level to the tops of two of the hills, one the highest on the island. It may be that there are low-lying tracts occupied chiefly by Carex, but so far as my investigations went, except where there was scrub, grasses and not cyperaceous plants abound, and the tussocks which densely clothe the mountains from summit to base are of grass and not of sedge, while small grasses of various kinds are by no means uncommon. Moreover, such tussocks are at the present time feeding 4,500 sheep, and this on at most only one-half of the island. As for the wet nature of the ground, it certainly does contain a great deal of moisture, but even in the middle of winter water cannot be generally wrung out of the peat; nor did any hole made by me in digging for plants fill with water, as, e.g., in the bogs of Chatham Island.
The lower tussock meadow forms a more or less distinct zone on the hillsides from the sea-level to a height perhaps of 150m., where it is succeeded by a second zone of meadow, to which I have given the name “subalpine tussock meadow,” above which comes a third but narrow zone where Rostkovia gracilis is the characteristic plant, while above and through this latter is the final zone, that of the rock-plants.
In no place where I was able to examine the lower tussock meadow was it in its virgin condition. Everywhere on Mount Honey, where at one time this formation must have been typical, have sheep grazed for some years, and their effect has been so marked that it is dealt with under another heading. But even now it is not hard to form a very fair
idea of what the virgin formation was like for although many plants are destroyed their remnants remain. Some few places still approximate to the primeval condition, and—most important of all—introduced plants have not as yet appeared in any quantity, and so increased enormously the difficulty of determining the character of the virgin formation.
The dominant plant is a tussock-grass with long narrow filiform leaves, probably a species of Poa—perhaps, indeed, identical with the meadow tussock of Antipodes Island, referred by Kirk to Poa anceps. My specimens, collected in midwinter, were too poor for identification; even Mr. D. Petrie, whose knowledge of the New Zealand grasses is so thorough, could make no definite statement as to the species.* By Mr. Gordon, of Campbell Island, it is called “silver-tussock,” and that name will serve admirably for the present.
With the silver-tussock is mixed occasionally a little Danthonia bromoides, and everywhere in the open spaces between the tussocks are the great colonies of Bulbinella rossii which attracted the attention of Hooker so that he wrote (46, p. 73), “It” [Bulbinella] “covered the swampy sides of the hills in such profusion as to be distinctly visible at a full mile from shore.” Similarly, the allied but smaller B. hookeri clothes many hillsides in the lower mountain region of the South Island with sheets pf yellow. In these same open places Pleurophyllum speciosum was very frequent, while the dark-green Aspidium vestitum, the brown-coloured Lomaria, procera, and prostrate bushes of Coprosma ciliata were common. These bushes are in some places flattened close to the ground; in other places, where the shelter is greater, they may be about 1.9m. long × 90 cm wide × 90 cm. tall. Their surface is sometimes flat, as if cut by shears, or at other times marked by long longitudinal ridges. They form extremely dense, large, flattened, pale-green hummocks, with bare, much-interlacing, rather thick, twisted branches beneath, looking not unlike stems of lianes; but the dense green surface, composed of quite small leaves, is at most 9 cm. or 10 cm. in depth. In some cases reversion-shoots are given off from the base of the plant, in the shelter and dim light of its interior, having very much larger leaves than those of the adult, and being almost identical with those of seedlings. In one seedling examined the stem was densely pilose; leaves ovate-oblong with rounded or cuneate base, pale-green, ciliated, a few hairs sometimes on the upper surface of the lamina, but always on the midrib. Petiole densely hairy,
[Footnote] * Since writing this Mr. Petrie informs me that the Antipodes Island tussock was the one be bad referred to Poa chathamica, but that he, and probably Mr. Cheeseman also, now considers it to be a new and unnamed, species.
3 mm, long; lamina 1.6 cm. × 1.1 cm., veins distinct. No pits, so common in Coprosma,* were noticed on the back of the leaf.
With the bashes of Coprosma ciliata, Aspidium vestitum is frequently mixed. Here and there, growing through the bushes or mixed with the tussock, were the rather shaggy naked stems of Veronica benthami, a shrub confined to the Campbell and Auckland Islands. These stems are marked with many old leaf-scars, but above are quite green. The leaves are crowded together at the extremities of the branches; they are thick, rather soft, narrow obovate-oblong in shape, dark-green, and their margins are edged with a pale-coloured tomentum. In size they are about 3 5 cm. × 1.4 cm. With regard to the light, the surfaces of the lower and larger leaves are horizontal or frequently arch downwards somewhat. The structure is that of a typical dorsi-ventral leaf. Nearer the apex of the shoot the leaves are smaller than those below, broader in proportion to their length, and loosely imbricating. The flowers are in racemes, which lengthen considerably during flowering, each flower subtended by a very large green leaf-like bract. The petals are a most clear violet-blue marked by very narrow lines of a still deeper blue.
Where the ground becomes wetter the character of the formation changes. There the surface is carpeted with the brown fronds of Lomaria procera, amongst and over which trailed the silvery-leaved Helichrysum prostratum. Through the Lomaria grow tussocks of Carex appressa.
The following extract from my notebook affords some idea of a general view of a piece of lowland meadow: “Large breadths of Lomaria procera mixed with stunted Carex appressa, low bushes 16 cm. tall of Coprosma parviflora, little conical cypress-like shrubs of Dracophyllum scoparium 30 cm. to 60 cm. tall dotted here and there, yellow tussock waving in the breeze everywhere except where Lomaria procera is abundant.” These little Dracophyllum shrubs have naked dark-coloured stems for half or less than half their height.
From the above it may be seen that there are two distinct associations of plants included under my term “lowland tussock meadow,” more or less sharply separated from one another by the amount of moisture in the ground: on the drier ground silver-tussock is dominant, and on the wetter a fern—Carex association. All the same, many of the meadow plants are common to both associations, and appear to thrive equally well either in the drier or moister ground. It must
[Footnote] * Greensill, N. A. R.: “Structure of Leaf of certain Species of Coprosma.” Trans. N.Z. Inst., vol. xxxv., pp. 342, 355. 1903.
be borne in mind that the term. “dry” is here merely comparative.
The soil of the formation as a whole consists of spongy peat, which is elastic underfoot. The surface is at first gently sloping, but becomes steeper as one proceeds up the mountain-side. Except within the gullies, and these in consequence filled with scrub, all the hillsides of Campbell Island must be much wind-swept; indeed, it seems evident that wind is here, as on the uplands of Auckland Island, the determining factor as to whether arborescent or grassy growth shall predominate.