XXXIII.-GUTTIFERÆ.
This is a small, strictly tropical, order, few being found to extend even a very few degrees beyond the tropics. For the most part it consists of trees, many of considerable dimensions, abounding in yellow resinous juice, that of some of the species, forming the well known Gamboge of commerce. The leaves are opposite, coriaceous, usually short petioled, simple, entire, I -nerved, with numerous transverse parallel veins, and without stipules. The flowers are either hermaphrodite or unisexual, either axillary, solitary, or racemose, or in terminal panicles ; occasionally in lateral fascicles.
Calyx free, often persistent, 2-4-6 or 8 sepaled, the sepals often coloured, resembling petals, imbricated by alternate pairs, the exterior ones often larger. Petals hypogynous, as many as the sepals, and alternate with them, or occasionally there are 4 in a 2-sepaled calyx, the outer pair passing insensibly into sepals. Stamens numerous, filaments either distinct, or combined into one, or four parcels, rarely definite; when unisexual, more numerous in the male flowers. Anthers adnate, one, two or 4-celled, bursting either lengthwise, transversely across the apex, or are circumsissile, sometimes, they open by a pore. Disk none, or prolonged in form of a rudimentary ovary in Mangostana. Ovarium solitary, superior, one or several celled, ovules solitary, or several, erect, or attached by the middle to a central placenta. Style none, or short. Stigma peltate, entire, or radiate and lobed. Fruit, either dry or succulent, one or several celled, with one rarely several seed in each cell. Seeds, frequently nestling in pulp, their coat thin and membranous apterous, frequently with an arillus. Albumen none. Embryo straight, cotyledons thick, inseparable : radicle either turned to or from the hilum.
Affinities. These have been already indicated under Ternstrœmiaceœ and Hypericineœ, the orders most nearly related to this, and the distinguishing marks pointed out : to these therefore I beg now to refer merely observing, that hitherto, so far as my opportunities of examining the Indian representatives of these orders extend, I have found no difficulty in discriminating between them. I do not mean by this to assert that difficulties are not found in distinguishing between these orders as now defined, but simply, that the Indian species seem mostly to appertain to the more marked, and least equivocal forms of each. Some further observations bearing on this subject will be found under the head of ' Remarks on genera and species' below.
Geographical Distribution. This, as remarked above is strictly a tropical order, very few species extending beyond that limit, Xanthochymus pictorius being mentioned by Mr. Royle as a remarkable exception, and my Calophyllum Walkerii may perhaps be adduced as a second example, for although a native of Ceylon, yet it is found only on the highest parts of the island at an elevation of about 7000 feet. These however can at best be considered as doubtful exceptions to the general rule, that they are confined to low moist localities partaking of a warm and humid climate, since neither can be viewed as genuine members of the order. This prediliction for warmth and moisture satisfactorily accounts for their predominance on the west coast of the Peninsula, where some species greatly abound, as compared with the east where very few species are found, and these very rare, being nearly confined to warm sheltered alpine valleys, enjoying a more humid climate than the plains. The southern provinces of Ceylon, Silhet, the Tenasserim coast, and eastern Archipelago, each partake largely of this order : wherever in short there is high temperature combined with much moisture there they are found. In tropical America they are said to be more numerous than in Asia, this however may be doubted, as it appears from Wallich's list of Indian plants, that including Xanthochymus he had no fewer than 40 Indian species ; while Mr. Don's system of plants, the last work published giving a complete catalogue of the order, has but 79, and these do not include several Javanese species published by Blume, to which it may be added, we have every reason to believe there are very many yet undiscovered in India and her islands, the Botany of every part of which has been less perfectly investigated than that of many parts of tropical America, though in truth, there is still a rich harvest for the enterprising Botanist in both countries. In continental Africa the order is nearly unknown, but several species are natives of Madagascar and the Mauritius.
Properties and Uses. DeCandolle remarks that without doubt the Guttiferœ would prove of great value, both for medicine and the arts, were they not exclusively confined to the warmest climates. As ornamental trees they are certainly not surpassed by any in the vegetable
