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New Zealand Plants and their Story

The Cabbage-tree

The Cabbage-tree.

The cabbage-tree (Cordyline australis) is a most familiar feature in almost any New Zealand landscape, while it is also a favourite adornment of gardens, supplying there a special beauty of form generally lacking in the temperate vegetation:

But, although the plant m question is known so well, it may yet be news to some that it is no relative of the wholesome vegetable whose name it bears. It, on the contrary, -belongs to the same family as the Madonna lily, the hyacinth, and the tulip; or, if we must seek its relations below stairs, then to the onion, the garlic, and the shalot, whilst amongst its first cousins it boasts such useful members of society as aloes, squills, and sarsaparilla. Now, it is the structure of the flowers which places it in this most distinguished company, the outer floral, leaves being united at the base,* but divided above into six segments, the stamens also six in number; while the central portion of the flower, which finally contains the seeds, is three-chambered. At the same time, it differs from most of its kith and kin in its possession of a tall, erect trunk, being, in fact, a tree-or palm-lily, this latter page 138designation having been bestowed on account of its tropical-looking habit, for it is not really a palm.

Fig. 60.—Underground stem of Cabbage-tree, with numerous roots.[Photo, L. Cockayne.

Fig. 60.—Underground stem of Cabbage-tree, with numerous roots.
[Photo, L. Cockayne.

The trunk plays a most important part in the domestic economy of the tree, sending down deep into the ground what is popularly supposed to be a root. This, however, is nothing of the kind, but a deeply descending underground stem, which has the curious property for a stem of growing downwards while the aerial portion of the same trunk grows upwards, as should that of any well-regulated tree (fig. 60). Such growing upwards and downwards of stems and roots is regulated by that force we call gravity, which sets in motion the intricate and powerful "machinery" of the plant, just as a pressure of the hand lets loose that power which causes the mighty locomotive to move backwards or forwards, as the case may be. The descending stem penetrates the soil for a distance of several feet, giving off on either side long cord - like roots, which, passing outwards page 139and downwards, anchor the tree firmly, so keeping it erect. But the underground stem, besides functioning as a natural prop for the tree, plays a further and more important part, since there is stored up within its tissues the surplus food, manufactured within its green leaves from the carbon-dioxide of the air by the aid of sunlight. On this hoard the tree draws yearly, and the material is lent from which the huge mass of flowers is constructed. Should too much of the starchy food be used, or not enough have accumulated owing to an adverse season, there will be few or no flowers the succeeding year. A sufficient balance must-be kept at its bankers, as it were, or its life work will remain undone.

The dead leaves of the cabbage-tree are scrupulously removed every year by the tidy but too zealous gardener, and a long, naked stem results. Nature, however, loves not nakedness in any form— the bare rock she clothes with lichens, and the fallen giant of the forest with moss; so, too, she hides-the upper portion of our tree's trunk with a not inelegant covering of brown dead leaves. Nor is she mindful of beauty alone in so doing, for these leaves become saturated with moisture when the welcome rain falls, the trunk on its part putting forth many short but active roots, which must assist the leaves materially to the all-important water-supply hi dry weather. As for the leaves themselves, they are provided with a strong, fibrous skeleton, which enables them to defy the frequent gales; also, they are more or less erect, and thus escape the full force of the sun's rays—a decided benefit in the long, hot summer days; and, finally, their minute structure is such as to guard them against excessive loss of moisture in times of drought.

The cabbage-tree blooms during November and December; the flower-stems are much-branched, and crowded with small whitish flowers. These have a most powerful, though rather sickly, odour, which attracts crowds of insect visitors, who in return for the gift of sweet honey assist in bringing the dust-like pollen of the stamens to the stigma, and thus fertilising the egg, which in due course will then grow into a seed—that is, into a small body containing within it a tiny cabbage-tree. The seeds are black in colour, and angular, nine or less being enclosed in the succulent, three-chambered, milky-white berries. These latter are greedily eaten by birds, who thus assist in sowing the seeds far from the parent tree. Not only do the native birds engage in this work, but the introduced ones have learnt also to page 140
Fig. 61.—The Broad-leaved Cabbage-tree, or Ti (Cordyline indivisa). Mount Hauhnngatahi.Lands Department.] [Photo, L. Cockayne.

Fig. 61.—The Broad-leaved Cabbage-tree, or Ti (Cordyline indivisa). Mount Hauhnngatahi.
Lands Department.] [Photo, L. Cockayne.

page 141play their part, and so there is little fear but that the cabbage-tree will always remain with us as a truly wild plant; in fact, in some parts of New Zealand it is on the increase, as in the swampy ground of northern Auckland, where, when the close-ranked kahikatea forest is felled, stately files of this graceful tree rise up in its stead.

The genus Cordyline is somewhat widespread, its species being found wild in southern Asia, the Malay Archipelago, the Pacific islands, Australia, New Zealand, and South America. The special species we are considering, C. australis, is confined to New Zealand; but, though it is extremely abundant in the two main Islands, and its fruits are readily spread by birds, it is found in only one locality in Stewart Island, and does not occur at all in either the subantarctic islands or the Chatham Islands.

There are four other species of Cordyline in New Zealand, one of which, the toi (C. indivisa) (fig. 61), is a magnificent object, with its broad, arching leaves furnished with a conspicuous orange-coloured midrib. It is common at rather high levels in the North Island, but descends to sea-level in the South at the Otago Sounds. On the east of the South Island are a few plants on Banks Peninsula. Where the service road to the Main Trunk line has been made along the base of ice-capped Ruapehu, and the forest has been cleared, are splendid natural plantations of this beautiful tree, which grows in some places, indeed, by the thousand.

The common cabbage-tree is easy of cultivation. It will grow in almost any kind of soil, and may be readily raised from seed, this being the best method to secure a stock of plants. When a tree is cut down level with the ground it does not die, but will usually put forth new shoots from the underground stem. Even at an early age it is very ornamental, and young specimens, whose trunks are not yet developed, are eminently suitable for small gardens. There is a purplish-leaved variety, and also one with variegated foliage. Moreover, the cabbage-tree is a variable species, and many forms distinct for garden purposes may be met with in the wild state.

In a land where the natural vegetable products were not of much economic value, the most unlikely plants were pressed into the service of the aborigines, and any possessing the slightest beneficial property were made use of. The cabbage-tree, or, as the Maoris designated it, page 142the ti, tikauka, or tirahau, served several purposes. The underground stem, since it contained a large supply of starch, supplied a nutritious if not an especially palatable kind of food, and the leaves were plaited into flat or round ropes. In the north, however, C. pumilio was much more prized for food. Cordyline indivisa was still more esteemed for its fibre, which, according to Colenso, was woven into a durable mat called toii, which was dyed black.

In Europe the cabbage-tree is much prized for horticultural purposes, though it is hardy only in the warmer parts. In the Scilly Isles it is used for hedges, making wind-screens to the fields of daffodils, there grown so extensively for the London market. Strange to say, many New Zealand plants, the cabbage-tree amongst the number, grow luxuriantly in the Isle of Arran, Scotland, which are only half-hardy farther south: a fact which recalls Stewart Island, where in certain parts trees peculiar to northern Auckland are cultivated with success, but which cannot endure the climate of the Canterbury coast.

* The coloured leaves of the flower in the lily family are in two series, and in certain of the genera are not united below into a tube.