New Zealand Plants and their Story
The manuka of the Maori, the tea-tree of the colonist, and Leptospermum scoparium of the scientist, should also be well known to every reader. Unlike the plants already dealt with, it has not suffered loss at the hands of the white man, but, on the contrary, has become aggressive, and at the present moment occupies more territory than in the pre-European days. This is owing to its power of thriving on any kind of soil, wet or dry, to the great fertility and number of its seeds, and to its habit of blooming at an abnormally early age for a shrub. The blossoms are distinctly showy—a manuka heath in due season being a sheet of snowy whiteness.
The flowers have a five-lobed calyx, the tube of which is attached to the ovary. There are five spreading petals and a great number of stamens. The fruit is a woody capsule containing many seeds, most of which are unfertile.
This structure of the flower shows the shrub to belong to the same family as the myrtle and rata in New Zealand, while abroad it has relatives in the gum-trees of Australia and the clove and allspice of the tropics.
Its leaves are small and stiff, and, like those of the family in general, extremely aromatic. This property has led to their use as a substitute for tea by the enterprising pioneers, who would probably cloak the unpleasant taste by means of no small allowance of sugar. From this use the English name "tea-tree" has arisen, and through corrupt spelling the spurious Maori "ti-tree" has followed, a term beloved of journalists. Worse than this is the usage in South Otago, where, "plain for all eyes to see," is the legend "Ti-Tri" on a certain wayside station.page 147
Like the flax and cabbage-tree, the manuka grows equally well on faces of rocks, in swamps, and on dunes, while in the Hot-lakes District it occupies a more inhospitable station still—the ground charged with chemicals near the boiling pools; in fact, few plants can so adapt themselves to varying circumstances—an important matter when one is concerned with the origin of species. As an example, it may be mentioned that on the central mountains of Stewart Island, where the wind blows with an almost incredible velocity, the manuka has changed its habit altogether, and, instead of being an upright shrub, lies prostrate upon the ground, as a far-spreading mat, its branches even near their apices putting out roots and fastening it to the soil. So different is this from the usual habit of the plant that one could hardly believe it to belong to the same species, were it not for the fact that all kinds of intermediate wind-shorn stages exist within a few feet of one another (fig. 62).
Besides L. scoparium, there are at least two other species in New Zealand—one, the tree-manuka or kanuka, a common plant enough; and the other, L. Sinclairii, only recorded hitherto from the Three Kings and the Great Barrier Island. The tree-manuka is distinguished from the commoner species by its larger size and its smaller stalked flowers, which are crowded together in great profusion, while the latter has larger, unstalked, solitary flowers. Both are very variable; but the most interesting varieties are those of the common manuka, which exhibit more or less red in their petals. Some are actually bright crimson, at least four such having been found, according to the author's knowledge, in the wild state.
These crimson varieties make beautiful garden plants. One, called by gardeners L. Chapmani, has been in cultivation for many years. Another, also with a garden name (L. Nichollsii), of more vivid crimson, is still handsomer. This, although introduced only a year or two ago, has already become established in a few English gardens, and is perhaps better known there than in its native land.
None of these red varieties seem to come absolutely "true" from seed, so they must be grown from cuttings, which unfortunately do not root readily. The red colour is present not only in the flowers, but extends to the leaves, which in all these races of manuka are more or less of a purple hue.page 148
Fig. 62.—Effect of Wind on Manuka (Leptospermum scoparium). All in foreground is Manuka, as well as the taller plants.
Lands Department.] [Photo, L. Cockayne.
There is also a form of manuka with double white flowers which was discovered a few years ago by Mr. E. Phillips Turner, Inspector of Scenic Reserves, but it has hardly got into cultivation as yet.
The common species of manuka are not nearly so much cultivated in gardens as they deserve. Not only are they extremely beautiful when in flower, but they will grow well in any kind of soil. Young plants may be procured from any heath in abundance, or raised from seed, which germinates readily.
One of the mistletoes is very frequently parasitic on Leptospermum scoparium. It is a very small shrub with curious jointed stems, but no leaves. It rejoices, or perhaps the contrary rather, in the name, much bigger than itself, of Korthalsella salicornioides. When this parasite becomes too abundant, the drain on the "life-blood" of its host becomes too great, and the branch supporting the mistletoe, or even the shrub as a whole, will die.
The common manuka (L. scoparium) has not usually a trunk stout enough to be of much use commercially, but it affords excellent firewood. It is also frequently used for brush fences, for the walls of whares, and for brooms, while the long straight poles are valuable for various purposes in gardens.
The colour of the wood differs in the two species. This has led to L. scoparium being called "red" and L. ericoides"white" tea-tree. As the leaves of both species are distinctly aromatic, a fragrant oil, which might possess medicinal properties, could be distilled from them.
The timber of the white tea-tree (L. ericoides) is of greater value than is that of its smaller relative. It has been used for wheelwrights' work, house-blocks, piles for small jetties, and fencing purposes. It also is highly valued for firewood.
The genus Leptospermum is made up of about thirty species, extending from New Zealand in the south to the Malay Archipelago in the north, by way of Australia and New Caledonia. By far the greatest number of species are Australian.