40 ILLUSTRATIONS OF INDIAN BOTANY.
prepared by being first soaked in strong alum water, the colour is then suspended in buttermilk, into which the cloth is dipped and charged with colour. The colour so imparted soon fades, and requires to be renewed from time to time, by a repetition of the above simple process.
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,
