XXVIII.-DIPTEROCARPEAE.
A small but, to Indian Botanists, highly interesting order being nearly confined to India and her islands. Two species only are noted as of foreign (African) origin. It is principally composed of large, handsome, fine flowering, trees, abounding in resinous juice. The leaves are alternate, marked with strong parallel veins, running from the midrib to the margin, furnished with deciduous, convolute, stipules, terminating the branches in a point: the racemes, of flowers are either terminal and panicled, or axillary, solitary, or several from the same leaves or from the axils, the flowers often secund.
Calyx persistent, somewhat tubular at the base, 5-lobed, lobes at first slightly unequal, afterwards enlarged, usually two of them much more so than the rest, becoming wing-like, æstivation imbricated. Petals hypogynous free, or slightly combined at the base ; aestivation twisted. Stamens indefinite, distinct, when numerous, attached to a broad somewhat elevated torus, occasionally irregularly polyadelphous ; when few, adherent to the base of the petals : filaments dilated at the base : anthers frequently terminating in bristle, or tipped with a gland-like point, 2-celled, opening by terminal fissures. Ovary few (3) celled, with two pendulous ovules in each : Style and stigma simple. Fruit coriaceous, I -celled, by abortion, 3-valved or indehiscent, surrounded by the calyx. Seed solitary, without albumen. Cotyledons twisted or crumpled, or unequal, and obliquely incumbent, radicle superior.
Affinities. In its affinities this order certainly claims close relationship with the Elaeocarpeae, but is yet perfectly distinct, the imbricate aestivation of the calyx, and the spirally contorted one of the corolla, affording ample grounds for their separation, notwithstanding the great similarity that exists between the stamens and pistils. The spiral aestivation of the corolla and crumpled cotyledons associate it with Malvaceæ, but the usually elongated 2 celled anthers, pendulous ovules, and imbricate œstivation of the calyx of Dipterocarpeae, keep them sufficiently distinct. With Guttiferae this order agrees in many points, more especially in its resinous juice, and exalbuminous seed, but is at once distinguished by its stipules, alternate leaves, and the very different aestivation of its corolla. " The enlarged foliaceous unequal segments of the calyx while investing the fruit, point out this family at once" (Lindley) and not less certainly, the inflorescence when in flower.
Geographical Distribution. The species of this order though few in number are yet spread over every part of India and her islands, from Ceylon and the southern promontory of the Peninsula, they extend northwards nearly to the foot of the Himalayas : and from the coast of Malabar, eastward, through Burmah, Siam, and Cochin- China, to Java. Roxburgh's catalogue of this order is very full, containing no fewer than 16 species, while Dr.Wallich's has only 19, several of these however were unknown to Roxburgh : whence, I presume, we may assume the number of Indian ones to amount to about 25 species. Blume has 4 from Java, but whether any of these are identical with any of the Indian species, I am not prepared to say, and to determine which, would require a more careful examination than I have the means of giving them. The genus Lophira having two species, both from Sierra Leone, is referred to this order. These are the only species, not of Asiatic origin, belonging to this family. In this neighbourhood (Madras) several species are found, but all natives of the hilly tracts forming the Balaghaut. In Silhet, Chittagong, and Pegue, wher* 3 they abound, they occupy the plains. In Java three, of the 4 species described, are natives of mountain forests, the 4th is found on the sea-shore, and hence has been by Blume called Dipterocarpus littoralis. A Hopea and Vateria India equally approach the coast in Malabar, but the latter is probably not confined to it, since either it, or one
very like, is found in Mysore. Two or three species are found in Goomsoor forming extensive forests, and affording to the inhabitants Incense, Dammer, and Wood oil. The imperfect descriptions of Dr Maxwell and Captain McPherson, ( Madras Journal of Science Nos. 18 and 19) to whom we are indebted for this information, does not enable me to determine the species, nor with certainty the genera, but judging from imperfect specimens collected by the former of these gentlemen, one of them belongs to Roxburgh's genus Shorea, apparently his 5.robusta, what the others may be, I am unable to form even a conjecture.
Both the authors mention Chloroxylon Dupada as being one of them, but this I think must be a mistake, originating in a statement of Dr. Ainslie, that that is the botanical name given to the Indian Dammer tree by Dr. Buchanan, but which, was an error of his, arising from his not being aware that several trees produce Dammer and that his Chloroxylon Dupada was already described by Linnaeus under the generic name of Valeria. The specimens sent unquestionably do not, belong to that genus, but as the inflorescence is in a very young state and there is no fruit, I do venture to say what they are, though 1 suspect them to be Roxburgh's Shorea robusta. From Ceylon the only ones I have seen are a species of Dipterocarpus ( D. turbinatus) and a new species of Vateria.
Properties and Uses. These are various and important. Almost every species of the order abounds in balsamic resinous juice, in very general use in every part of India, and well known to Europeans under the common English names of Dammer, and Wood oil, according as it hardens or remains fluid on exposure to the air. That drawn from the Shoreas or Vaticas and Vaterias hardens and forms Dammer, and Piney, that from Dipterocarpi retains its fluidity, and is the Wood oil, of the bazaars. Some of the species produce a fragrant resin, which is burnt in the temples as Incense. Dammer is used in India for most of the purposes to which pitch and rosen are applied in Europe. Wood oil either alone, or thickened with dammer, supplies a common, but useful, varnish for wood, possessing the valuable property of, for a long time, repelling the attacks of white ants, as well as of resisting the influence of the climate. The Camphor tree of Sumatra is a species of Vatica, (Shorea camphorifera, Roxb.) and produces the finest camphor. A variety of other trees are said to afford this curious substance, but none equal to this, either in quality or quantity. The Vateria lndica (Chloroxylon Dupada, Buchanan and Ainslie, and Pinne marum of the Hindoos) produces a resin, resembling Copal, much finer than that procured from the other species natives of India, the finer specimens of which are as transparent as amber, and nearly colorless. It is procured by the very simple process of cutting a notch in the tree, sloping inwards and downwards. This is soon filled with the juice, which in a short time hardens by exposure to the ail. When used as a varnish the usual practice is to apply the balsam before it has become hard : but when that is not procurable the resin melted by a slow heat and mixed with boiling Linseed oil forms a varnish which answers equally well for most purposes.
As this varnish is of the finest description the following formula for its preparation may prove useful to some who are unacquainted with the process. Into a new and perfectly clean earthen vessel (a chatty) put one part of the Piney dammer, in coarse powder cover closely, and apply a very gentle heat until the whole is melted ; then add about two parts of linseed oil, nearly boiling hot, and mix well with a wooden spathula. Should the varnish prove too thick it can at any time be reduced by the addition of more oil, or if required may be made thicker in the first instance.
It is essential to the success of the process that the Piney be melted in a covered vessel over a very slow fire, and the whole of it reduced to a fluid before the addition of the oil, which must, to ensure an equal mixture, be nearly boiling hot. This varnish is used for carriages and other fine furniture requiring to have their paint well protected, or to which it is desirable to impart a fine gloss.
A spirit varnish is prepared by reducing to powder about six parts of Piney and one of Camphor, and then adding hot alcohol sufficient to dissolve the mixed powder. Alcohol does not dissolve Piney without the aid of the Camphor, but once dissolved will retain it in solution.
The varnish thus prepared is employed for varnishing pictures, &c, but before being used requires to be gently heated to evaporate the Camphor, which otherwise will produce by its after evaporation a roughness and inequality on the surface of the picture, and spoil its appearance.
In addition to these more common applications of Piney, it is, on the Malabar coast, made into candles. These diffuse, in burning, an agreeable fragrance, give a fine clear light, with little smoke, and consume the wick so as not to require snuffing. For making them the fluid resin may either be run into moulds, or when yet soft and pliable. in course of hardening, be rolled into the required shape. Some of these candles that were sent home, were highly prized, and sold for very high prices, but the protective duties on made candles, imported into Britain, is so high, as to amount to a prohibition, and put a stop to this trade. The crude Piney is however still sent for the purpose of being manufactured at home.
The medicinal properties of Camphor are too well known to require notice here, and those of Dammer are as yet but little known. The late Dr. Herklots directed attention to a native remedy for Berriberri Chloroxylon, black or Liniment the basis of which is Dammer, and gave a formula for its preparation, which has been published by Mr. Malcolmson page 328 of his essay on Berriberri. Both these gentlemen recommend it as a useful auxiliary in the treatment of this most fatal disease. Of its merits, I am unable to speak from personal knowledge, as I have never seen it used, nor indeed have ever seen the medicine, but Mr. Malcolmson seems to think it preferable to the liniments in general use, among us, for most cases requiring that kind of stimulus.
As nearly all the plants belonging to this order are trees, among the most majestic of the forest, they are esteemed for their timber, as well as for their resinous juice, and the well-known Saul, Shorea robusta Roxb. is considered by that eminent naturalist as only second to Teak, for most purposes requiring a strong durable wood. As ornamental trees they merit much attention, not only on account of their majestic size and handsome forms, but equally for the beauty of their clustered flowers, and the richly colored wings of their curious fruit. Both the Hopea, and Vatica Tumbugia (see Icones) are found in the vicinity of Madras, and might, I presume, be easily introduced into our gardens, where I have no doubt they would be much admired. Whether the Piney from Malabar would equally succeed is doubtful, but it is well deserving of a trial, since it is scarcely exceeded in beauty by any other tree.
Remarks on the Genera and Species. The genera of this order are few in number, and generally agree so nearly in their distinctive characters that one is almost led to doubt whether they ought all to be retained. Dr. Lindley enumerates five, four of which are Indian. These may be thus distinguished. In Vateria, all the sepals more or less enlarge with the fruit, but do not form membranous wing-like appendages. In Hopea and Dipterocarpus, two of the sepals enlarge, and become dry scariose wings : the former is further distinguished by having 10 compressed filaments adhering to the base of the corolla and 15 short anthers, each alternate filament bearing two anthers, to which may be added as supplementary characters, the nearly sessile secund small flowers, greatly twisted aestivation, and union, at the base, of the petals : the latter, by having fewer and larger flowers, slightly twisted aestivation, and numerous filaments, each bearing a single elongated anther. In Vatica Lin. (Shorea of Roxb. and others) all the sepals, more or less enlarge, and become wing-shaped ; the stamens vary much in number, but are generally numerous. Dr. Arnott and I remark (W. and A. Prod.) that Valeria lanceœfolia Roxb. " ought perhaps to form a distinct genus," since then I have received specimens of a very nearly allied species ( V. Roxburgii R. W. Icones, No. 26) a native of the Peninsula. From an examination of this plant I still feel disposed to adopt the opinion then expressed, as there are points of difference, I think, of sufficient weight to separate them, but on the other hand a slight modification of the generic character suffices to keep them together, and as they essentially agree in the character of the calyx, both when in flower and in fruit, and that being the organ from which the generic distinctions of the order are principallly derived, 1 prefer leaving them in the genus, but forming for their more easy accommodation a subgenus; a plan, in which I was happy to find myself anticipated jby Dr Arnott, from whom. I received while this was passing through the press, a synopsis of the genus so arranged. V. ceylanica which I have added is exactly intermediate between his two subgenera, having the elongated style and acute stigma of the one, and the stamens and axillary inflorescence of the other. The fruit I have not seen, and the flowers not being full blown in the only specimen I have examined, it is too imperfect to enable me to determine the point, but I think it probable the species will, when better known, form the type of a third subgenus.
I mentioned above that Vateria indica was probably a native of Mysore. This opinion rests on some well executed drawings and specimens communicated by Mr. Apothecary Bertie*
- I am indebted to Bertie for several very well executed drawings of plants and trust that my expectations of receiving many more will not be disappointed. An accomplishment so rare among the members of his branch of the service merits public commendation. under the name of Dhupada Mara. The specimens are not in flower, and the representation of the flowers is not accompanied with such details and analysis as to enable me to say, with certainty, whether the Mysore and Malabar trees are the same or distinct species, there are differences in the form of the leaves that give rise to a suspicion that they are different, but these I do not think sufficient to establish the point. This I presume is the true Chloroxylon dupada of Buchanan, a really good figure of which it is most desirable should be published, even at the risk of republishing in outline, what has been already published as a coloured plate. Under this impression, I trust the same liberal hand which has enabled me so far to verify the tree meant by Buchanan (afterward Hamilton) as the Dammer tree of India, will enable me to do the rest by finally determining the species. This seems much wanted, since, in the present imperfect state of our knowledge, every plant of this part of India from which a concrete resinous juice is procured, and these are many, is at once designated Chloroxylon dupada from that circumstance alone.
My suspicions of the Mysore species being different from the Malabar one, are strengthened by the circumstance of a species, quite distinct from V. indica, but very closely resembling, in general appearance, the Mysore form, being found in Ceylon. The difference between the Ceylon and Malabar plants lies in the stamens, and cannot be seen without; careful examination, those of the Ceylon species ( V. Ceylanica, R. W.) being few, (15) sessile, tomentose, with a very short almost imperceptible prolongation of the point ; while in V. indica, they are very numerous, supported on a distinct filament, glabrous, and terminating in a long slender bristle point. There are besides differences in the leaves, but these I consider of less value as a specific distinctions than the peculiarities of the flowers.
Among a collection of plants from Mergui, for which I am indebted to my friend Mr. Griffith, I observe specimens of some new species of this order, but which I do not consider myself at liberty to name or describe, as I presume it is his intention to publish descriptions of the whole of his now vast collections, amounting, I understand, to between 7000 and 8000 species. The species of Hopea are as yet few, but will, I think, be found more numerous when the characters are better understood, at least my specimens, which are numerous, present such variations of form, as renders it probable, there are more than one species, but as yet, I am unable to dis- entangle them. The dissected flower of the accompanying figure, if correct, seems to indicate that the plant figured is distinct from all those in my collection, in having only 10 anthers in place of 15, the usual number ; namely, 5 simple filaments, with single anthers, and 5 cleft ones, each bearing two anthers. There is a species in Mysore which Dr. Buchanan Hamilton has named H. decandra, but of which he has given no description : this may be that plant, but I rather think the deficiency is referable to an error or oversight of the artist, and which was not detected in time to prevent its being printed. In addition to the Peninsular ones there are two from Mergui, but none have yet reached me from Ceylon.
VATERIA.
Subgenus I. Euvateria (Arn.) Segments of the calyx scarcely enlarging when in fruit, obtuse. Petals oval, scarcely longer than the calyx. Stamens 40—50 anther cells linear. Style elongated, stigma acute. Panicle large terminal.
1. V. Indica. Lin.
Subgenus II. ISAUXIS (Arn.) Segments of the calyx enlarging when in fruit, ovate, acute. Petals falcate about three times the length of the calyx. Stamens 15, anther cells oblong. Style short. Stigma clavate 3 — 6 toothed. Panicles axillary shorter than the leaves.
2. V. lanceœfolia. Roxb. Leaves lanceolate, acute at the base.
3. V. Roxburghiana R. W. Leaves ovate, oblong, retuse, or obtuse at the base.
? 4. V. Ceylanica R. W. Leaves obovate, very obtuse, retuse at the point, narrow at the base : anthers hairy, stigma acute.
EXPLANATION OF PLATE 36.
1. Flowering branch of Vateria Indica— natural sie. 2. Calyx, corolla and anthers. 3. Ovary, style, and stigma, with two stamens left to show their hypogynous insertion. 4. A branch of the panicle in fruit.
5. A fruit cut transversely, showing the irregular form of the cotyledons— all more or less magnified. DIPTEROCARPEÆ.jpg)
VATERIA INDICA (Linn.)
DIPTEROCARPEÆ.jpg)
HOPEA WIGHTIANA (Wall.)
EXPLANATION OF PLATE 37.
1. Flowering branch of Hopea Wightiana—natural size.
2. Ovary and sepals.
3. Corolla and stamens: the latter perhaps incorrectly represented — see remarks page 38.
4. A detached stamen.
5. Ovary cut transversely.
6. A fruit showing the wing-like enlargement of the sepals.
7. A seed cut transversely.
8 and 9. The testa removed, showing irregular forms of the cotyledons and superior radicle.
10, 11, 12. Sections of the fungus-like excrescence on the branch, which seem to indicate that it is an abortive panicle, perhaps rendered so, through insects forming their nidus in the bud.