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ILLUSTRATIONS OF INDIAN BOTANY.
found on the Himalayas, but only one, so far as I am aware, extends to Southern India, and these only met with on tops of the highest mountains. Species of Exacum extend from the level of the sea to the highest tops of the Neilgherries ; the Canscoras are all natives of the plains, or of lower elevations ; the Ophelias, several of which are found in the peninsula, inhabit the mountain tops, as does Halenia, a nearly allied genus. The aquatic genera, Villarsia and Limnanthemum, I have always found on the plains.
Properties and Uses. On this subject Lindley well remarks, that "the order of Gentianece is not more remarkable for the diversity of its colours, than it is for the uniformity of the secretions which its various species exhibit. Bitterness in every part, roots, leaves, flower, fruit, in annuals perennials and shrubs, is so much their characteristic, that the following account of the purposes to which they are applied is little more than a list of repetitions; with this exception, that they in some cases prove narcotic and emetic.'"
The properties of the Indian species, with the exception of a few of the northern ones, seem to have been scarcely if at all investigated, as I do not find a single notice regarding them, but I know that they do not depart from the general characteristics of bitterness as I have tasted many. Neither have I in this country seen them in cultivation as garden orna- ments, though several merit the distinction, especially the Exacums, which replace in this country the Gentians of Europe. Their colours as indicated, in the above extract, by Dr. Lindley are various and striking ; red, purple, blue, yellow, and white all occur, and in one Indian species, Exacum bicolor, blue and white are blended, the tube of the flower being white, and the tips of the lobes blue. The flowers of the little, Neilgherry Gentian are deep-blue, and so likewise are those of the much-more-conspicuous and showy Exacum Perrottetii, a most ornamental plant, but rarely met with in gardens. The Ophelias too are all showy plants, and with a little care might be rendered very ornamental additions to the flower garden.
Remarks on Genera and Species. To this order appertains about 60 genera, and nearly 500 species ; of these 12 or 13 genera, and about 100 species are found in India. Griesbach divides the order into two tribes, Gentianece verce and Menyanthece. The first of these tribes he further divides into 4 sub-tribes, three of which have Indian representatives. For the pur- pose of conveying as perfect an idea of the whole order, as can be done in small space, I have selected small plants for representation in the supplementary plate, and in that way have been enabled to illustrate both the tribes and three of the sub-tribes in a single plate. Those wishing further information will find figures of 20 additional species in my Icones. Regarding the plant figured in the Icones under the name of Halenia Perrottetii, I may here remark that I have, since its publication, ascertained it is not that species but H. elliptica (or a nearly allied species) which thus, if really identical, proves to be a native of both the Himalayas and Neilgherries. Still further to correct the previous error, I have given a figure of what I consider the true plant in the accompanying plate, No. 157. The following are Griesbach's characters of the Tribes and Sub-tribes illustrated.
Tribe I. Gentianece. Estivation of the corolla twisted to the left. Testa membranace- ous. Terrestrial herbs, or rarely shrubs. Leaves opposite (very rarely alternate), entire.
Sub-tribe I. Chironiece, Cells of the anthers erect, without a connective, hence dehiscing by short, pore-like slits, often contiguous at the apex. ( Exacum Perrottetii.)
Sub-tribe II. Chlorece. Anthers furnished with a connective, at length recurved or spirally twisted. Style distinct, deciduous. ( Canscora alata and Cicindea fastigiata.)
Sub-tribe IV. Swertiece. Anthers furnished with a connective, remaining unchanged. Stigma persistent, sessile, or the style persistent and confluent with the lobes of the stigma. (Halenia Perrottetii, and several species of Ophelia.)
Tribe II. Menyanthece. ^Estivation of the corolla induplicate. Epidermis of the testa ligneous. Herbaceous, aquatic or marsh plants. Leaves alternate, sheathing. ( Limnanthemum cristatum.)
Under these divisions 44 genera are arranged, with a few only of which I am acquainted, but, slender as my acquaintance is with the order, as a whole, I cannot help thinking that some
