The altitude of the mountain ridges in Penang is not so great as to produce a very marked difference in the geographic distribution of its vegetable productions. The highest point of land is that on which the flag-staff is placed; and this, by barometric measurement, gives an altitude of two thousand two hundred and twenty-three feet, above the governor’s house, which may be reckoned about twenty-five feet above the level of the sea; so that the greatest altitude will be two thousand two hundred and forty-eight feet. Within this space, however, the more experienced botanist, will detect a sensible difference in the distribution of the vegetable forms. In the low grounds which extend from the sea coast to the base of the hills, and for some distance up their flanks, he will recognise the favoured region of the Palms, and of the greater number of the Scitamineæ, vying with the former in utility, whilst they even excel them in the beauty of their general appearance.
Of the intertropical plants, the most superficial observer will have remarked, that a considerable proportion are influenced scarcely less in their geographical distribution by longitudinal than by latitudinal position; and, if we divide the globe into hemispheres, we shall find that the plants of an eastern differ from those of a western hemisphere scarcely less than those of the northern from the southern. We may thus observe a constant tendency to confine plants to a particular spot, to isolate, and to increase their number; and that though, like man, some are capable of existing in a great variety of climates, yet that these are to be considered as exceptions to a great and general rule. Within the tropics this limited distribution of plants is more remarkable than in the other zones. It is especially observable in the distribution of Palms, Scitamineæ, and the more valuable spices and aromatics. Heat alone is not sufficient for their production, or we should find them more general throughout the torrid zone, while, in fact, they are respectively confined to very narrow limits. Within the tropics, from the equator to nearly 20° N., and on the level of the ocean, or but slightly elevated above it, we distinguish a belt, within which are contained almost all the Palms with which we are acquainted. They constitute the most remarkable vegetable production within this space. As to distribution, we notice various points at which, without apparent alteration of temperature, they are respectively limited.
Of the Cocoa-nut we may remark, that it grows with the greatest luxuriance and perfection in the Maldive and Laccadine Islands, on the south and west coasts of Ceylon, on the coasts of Malabar and Coromandel, and west as far as Bombay. At Penang this Palm is evidently less productive, and therefore less extensively cultivated. It is replaced by the Areca catechu; by Nipa fruticans, Cycas circinalis, and a few others. The Sea Cocoa-nut, as it is called, is still more limited in its distribution; and the Borassus gomutus is almost equally so. Here, too, it is rare to see a single specimen of the Borassus flabelliformis, a palm so common in other parts of India. Peculiarity of soil does not appear to be the sole cause of the occurrence of some, or of the want of other species of the Palm tree. The soil of Penang and of the opposite coast is of various descriptions and qualities, and probably suited to the production of the whole tribe, being in some parts sandy, hard and poor; in others, of a stiff, iron-coloured clay; in others, soft and spongy, constituting extensive morasses; in others, thick, black, and rich, containing a large proportion of vegetable matter.
It has been remarked, that the mountain ranges are but of moderate altitude, and that, therefore, we must not look for very great or striking differences in the distribution of vegetable forms, as connected with this circumstance. Arborescent vegetation here exists in its fullest vigour, to within two or three hundred feet of the summit of the loftiest peaks; and it may be observed, that the forests generally abound in wood of uncommon altitude. At the elevation of nearly one thousand feet, a considerable number of diminutive, but elegant herbaceous plants are to be found, which do not occur at a less elevation, and we meet with several species of Ferns in the same situation. The gigantic Grasses of the plains here cease to grow: Parasites, Epidendra, and Contortæ increase in number. Within a few hundred feet of the summit we find an arborescent Fern of great magnitude, and a species of Yew is said to occupy a similar range on a contiguous hill. On the summit of the two highest peaks, arborescent vegetation is evidently stunted, and the trees are of shrubby forms, yet the productions of the plains will here thrive, with the assistance of cultivation. We found Canna indica, Carica, Mussænda frondosa, and various other plants growing around the Bungalows built upon the summit of the principal peak. This elevation must certainly afford a fine prospect from its summit, but as we were unfortunate in the state of the weather at the time of our visit, I am not enabled to speak duly in its favour.
The agricultural produce of this island is but inconsiderable; and although much care is at the present time bestowed in clearing the hills, for the purpose of introducing the cultivation of Coffee, Spices, &c., the success of the experiment must as yet be left for the ascertainment of futurity. The labour and expense of clearing steep hills of exuberant woods must necessarily be very great; and where arborescent vegetation exists in such vigour, it will always be a matter of much difficulty to prevent the ground becoming again rapidly covered with forest. It is to be feared, too, that the sloping sides of granitic hills will not long continue favourable to the growth of plants requiring a peculiar soil, and modified by the care bestowed upon them by man. It is known that the more valuable productions of the botanical world require the richest soil, and most assiduous and unremitted care on the part of the cultivator. They have, in fact, become, in a great measure, the work of his own hand; in their perfect condition frequently incapable of maintaining their existence independent of his care. When abandoned, they soon revert to their original meagre condition, with difficulty to be identified with the cherished product of cultivation, whilst of some plants, as of the more valuable of the Cerealia, we look in vain for the parent stock. Hence it is, that disregarding or forgetting this fact, we are apt to consider the soil as excellent which supports that astonishing quantity of vegetation we observe throughout these islands. To enumerate the useful and curious plants this island produces, either spontaneously or by culture, is a task too extensive. Pepper is the principal article. It is produced principally on the southern parts of the island, on the slopes of low hills, and on the narrow level belt which intervenes between them and the sea-shore. The cultivation is almost exclusively in the hands of the Chinese, who conduct it with a degree of art and neatness, unknown in any other part of the East. For an account of the cultivation of pepper, see Marsden’s History of Sumatra. The plants are supported on the stems of the Erythrina indica, and occasionally on those of the Morinda citrifolia, which are planted with them for this purpose. The Nutmeg may be considered as the next in importance of the agricultural products. Its cultivation is, on the whole, attended with considerable success; the trees are large, vigorous, and produce a great quantity of fruit, yet it has required upwards of twenty years to give earnest of success; and it is stated, that as yet no exportation of this article has taken place. The number of trees, at present on the island, is rated at one hundred and fifty thousand, of which one-third only are in a condition to bear fruit. Mr. Brown states the produce of a single tree at one thousand nuts annually, and this number is at present sold in the market for five Spanish dollars, and the mace, which amounts to about one-fourth of the weight of the nuts, is sold for something more than the above-mentioned sum. The first fruit is reaped after the seventh year.
The Clove is also cultivated with success. Some trees which I have seen growing at the base of the hills, and on the skirts of the forest, where they were planted under the shade of other trees, seemed to flourish with great vigour.
Mr. Brown states the produce of a single Coffee plant at four pounds.
We were too late to enjoy the Mangosteen in its greatest perfection, yet from the few which were still to be procured, we considered it well entitled to the encomium so often bestowed upon it by travellers.
I proceed to mention the more general plants used in the domestic economy of the natives.
Pandanus lævis – the leaves afford a strong cordage, used for making nets and other purposes.
A species of Urtica is cultivated for a similar purpose.
Nipa fruticans – the leaves are used universally for