Illustrations of Indian Botany, Vol. 1/Violarieae
XVI—VIOLARIEAE.
A large and widely distributed order, its species being found in almost every part of the world, but most abundantly in America. A few only have as yet been found in tropical Asia. Those of India, like the European ones, are all diminutive herbs or suffruticose plants, but the American ones attain the size of considerable shrubs or even small trees. The leaves are usually alternate, stipulate, simple : the flowers erect, or spreading peduncled : the peduncles solitary, or several together, 1-flowered, with two bractioles. The calyx consists of 5 persistent sepals, imbricated in aestivation : the Corolla of 5 inferior petals, sometimes unequal, usually withering and obliquely convolute in cestivation : the Stamens 5, alternate with, rarely opposite, the petals, inserted on an inferior disk, often unequal, with the anthers sometimes co-hering, lying close on the ovary, 2-celled, opening inwardly, and tipped with membrane; two of the filaments in the irregular flowered ones, furnished with an appendage or gland at the base : the Ovary 1-celled, usually many seeded, with 3 parietal placentas, opposite the three outer sepals; Style single, declinate, with an oblique hooded stigma : Capsule, 3-valved loculicidal, bearing the placentae on the middle of the valves : seed often carunculate at the base, having a straight, erect, embryo in the axis of a fleshy albumen.
Affinities. Polygaleae and Droseracece, are considered by DeCandolle and others the orders most nearly allied to this, which however can only be with reference to the extreme forms, which are not met with in India. The Indian genera can scarcely be confounded with them, the Violariece being all furnished with a 3-valved capsule, bearing the placentas, and numerous seed on the middle of the valves. While in Polygaleae, except Xanthophyllum, which has an indehiscent fruit, the capsule is 2-celled, with a single pendulous seed in each cell, and the Droseraceae have several styles, cercinate vernation, and ex-stipulate leaves. The most nearly allied orders so far as the Indian flora is concerned, being thus easily distinguished, it is unnecessary to enter further on their distinctive marks, with reference to those of other countries.
Essential Character. Polypetalous : stamens fewer than 20 : ovary superior of several carpels, combined into a single capsule, with more placentas than one. Leaves dotless, straight when young, furnished with stipules.
Geographical Distribution. As already observed the species of this order are met with in every part of the world, but certainly predominaie in America, and there they attain their greatest development; large shrubs and even moderate sized trees being found among the American representatives of the order. In Europe, as in India, the forms of Violarieae are either herbs or small shrubs, the latter however, with much smaller flowers than is usual in the former. Of the whole namber of known species of the order, the Indian flora, taking Wallich's listas the standard, contains about 1-1 0th. These are referable to three genera, viz. Viola, Ionidium, and Pentaloba, the latter genus as yet unobserved in the Peninsula. Of these, the species of Viola always occupy alpine situations, while the two species of Ionidium, are both natives of the plains. Pentaloba is found in Bengal and in Cochin China; species of Viola and Ionidium are also found in Java.
Properties and Uses. Under this head we possess little information derived from Indian experience, two species only being met with on the plains, and these small plants, but little regarded. They are however members of a genus (Ionidium) remarkable for the number of its species, endowed with rather strong emetic properties, so much so indeed is the case with some of them, that it was long supposed the tree Ipecacuana was derived from one of them, which hence got the name of Viola (Ionidium) Ipecacuana, and in Brazil they are said to be in common use as emetics. Those of this country are not stated by Ainslie to have any such properties, but he speaks of the leaves and young shoots as being demulcent, and adds, that formed into a liniment with oil, the natives esteem them a cooling application to the head after exposure to the sun, and I am informed that the leaves and young shoots are eat as a cure for ardor urinae and gonorrhoea. On the continent of Europe, decoctions of the sweet smelling and pansy violets, are extensively employed for the cure of cutaneous affections, particularly of children: whether our alpine violets, of which our hills produce several species, will be found suited for such purposes remains to be determined.
M. Boullay (Jour. de Pharm. X, 23) discovered in the Viola odorata an alcaloide, so analogous to emetine, that he called it emetine de violette, or violine. He considers it not as identical with that procured from Ipecacuana, but as a species of the same genus. He obtained it in two states; 1st. Impure violine, combined with malic acid, in form of yellowish brown deliquescent scales, very soluble in alcohol. Of this a pound of violet roots treated with alcohol, furnished about 4 drachms. 2d. Pure violine. The taste is bitter, very acrid, and disagreeable; it is in form of a white powder; little soluble in water, but more so than emetine, less soluble on the contrary than it in cold alcohol, insoluble in aether, and in the fixed and volatile oils. It combines with acids but does not form well characterized salts. It possesses strong emetic and purgative properties, but was found when tried, very uncertain in its operation, and was never admitted into practice : but the fact of one of the least active of the order being endowed with such properties, affords strong grounds for inferring that most of the others possess them in a greater or less degree.
Remarks on Genera and Species. As there are only two genera of this order found in Southern India, a species of each of which is here figured to show their distinctive characters, it appears unnecessary to advert here to their generic characters. Specific characters however are not so easily made out, owing to their disposition to vary, under this conviction, I was at first led to conclude that the species here figured, was one of the numerous varieties of Viola Patrinii, and it was not until I had examined, with much care, a great number of specimens, procured from different localities, I became sensible of my error, by observing that, however much they varied in other respects, they all agreed in having winged-leaf stalks. The absence of that character, combined with the whole under surface of the leaves of this one, being covered with short hairs, (in V. Vatrinii they are confined to the veins only,) aided by its remote place of growth (Ceylon) induced me to take a different view, and consider it a new species. Viola Patrinii except in the characters above alluded to is most variable. In some of my specimens the petiols are shorter, others longer than the limit of the leaf, and the leaves in place of being always truncated are occasionally cordate at the base, in others the petiols are nearly a foot long, surmounted by triangular leaves, not above an inch and a half in their largest dimension, while in a third form the leaves more nearly approach to lanceolate, that is, they taper at the base ; but still the winged petiol is invariably present. These various forms are derived from the Neilgherries, Pulney mountains, and Shevaroy hills—the very large ones are from the last named station. The relative length of leaves and peduncles do not afford good distinctive marks, the one being sometimes longer, sometimes shorter, than the other. To the species here figured may probably be referred the Viola hastafa of Moon (Gal. Ceylon plants). The species variously named Viola serpens, V. aspera, V. crenata, V. Wightiana, and V. palmaris, are I suspect only varieties of one species, and feel almost certain, that my collection presents representatives of each, though I am unable to distinguish two well marked species among the whole, without however wishing for the present to do more than call attention to the subject, I may observe, that characters taken from the comparative lengths of petiols and peduncles, are scarcely fit to determine specimens of the same plant for they vary in their relative proportions on different parts of the same specimen, neither do I think, are good characters to be obtained from the stipules or bractioles, which appear to be nearly the same through the whole series. The degree of hairiness is equally variable even on the same plant, apparently depending on different degrees of luxuriance, the early leaves, expanded under the influence of a moist soil and atmosphere, being sometimes nearly glabrous, while others developed at a latter period, probably during dry weather, are decidedly hairy. Again they all agree in their sarmentose habit and cordate leaves, but the form of the leaves differ, for sometimes they are broadly reniform cordate at the base, and obtuse at the apex; others are simply cordate, with a tendency to accumination at the apex, while in others they are distinctly accuminated and very sharp pointed : some specimens have acutely serrated leaves, others crenated, while in others again they are almost entire on the margine. The series of specimens upon which these observations are made were derived from the Neilgherries, Pulney mountains, Shevaroy hills, Shevagherry hills, and Ceylon, to which I may add, that Mr. Royle's figure of the Himalayan form, perfectly corresponds with my native specimens derived from the above localities. The following characters will, I hope, sufficiently distinguish the new species from V. Patrinii.
Viola Walkerii. (E. W.) Stemless, leaves oblong, cordate at the base, crenate, petiols short, wingless : peduncles much longer than the leaves, stigma margined.
I have dedicated this species to Col. Walker from whom I first received specimens, and from one of which the accompanying figure was taken. them in the character.
Viola Patrinii (D. C.) Stemless, leaves truncated at the base, from oblong, to nearly triangular, sometimes longer (but usually much shorter) than the petiol, petiols winged.
Neilgherries, &c. The peduncles being either longer or shorter than the leaves, I have not referred to them in the character.
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VIOLA WALKERII. (R. W.)
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IONIDIUM SUFFRUTICOSUM.