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Page:Illustrations of Indian Botany, Vol. 1.djvu/106

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ILLUSTRATIONS OF INDIAN BOTANY.

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, Viola Patrinii (D. C.) Stemless, leaves truncated cordate at the base, crenate, petiols short, wingless : at the base, from oblong, to nearly triangular, some- peduncles much longer than the leaves, stigma mar- times longer (but usually much shorter) than the gined. petiol, petiols winged.

I have dedicated this species to Col. Walker from Neilgherries, &<:. The peduncles being either whom I first received specimens, and from one of longer or shorter than the leaves, I have not referred to which the accompanying figure was taken. them in the character.

XVII.— DROSERACEAE — THE SUN-DEW TRIBE.

A small order of herbaceous, annual, or perennial, rarely sufFrutescent plants, with simple, rarely pinnatifed or toothed, alternate, leaves, often congested at the base, for the most part furnished with scattered glandular hairs, especially on the margins, and with circinate verna- tion, the leaves being rolled inwards from the apex towards the base like ferns, stipules want- ing, but in their place often furnished with stipulary hairs at the base of the petiols. Their flowers are hermaphrodite, regular, either solitary, or more frequently racemose, pedicelled, all ranged on one side of the stalk, (secund) the stalk circinatety revolute before the expansion of the flowers. The calyx free, persistent, consisting of 5 equal imbricating sepals : the corolla of 5 hypogynous equal petals, which continue to adhere and wither on the stalk after blooming, (marcescent.) The stamens usually equal the petals, and alternate with them, but are some- times double or treble the number, with terminal, erect, 2-celled, anthers ; bursting longitu- dinally, or rarely, by terminal pores. The ovary is sessile, I -celled, with parietal many seeded placenta?, styles 3-5 distinct, or co hering at the base, with bifid or branched stigmas. Fruit capsular, 1 -celled, 3-5 valved, dehiscence loculicidal, that is the valves bearing the placentas, and seeds on their middle. Seeds numerous, minute, albumen fleshy or cartilagenous, enclosing the straight Embryo, with its radical pointing towards the hilum : cotyledons thick, becoming foliacious in germination.

Affinities. This order is nearly allied to Violarieoe, from which however it is distin- guished by its circinate vernation, ex stipulate leaves, and numerous styles. Dr. Lindley con- siders them also related to Sa^ifrageee, from which they are principally distinguished by their vernation. He however refers Parnassia to that order, though it agrees with Drosera in its vernation, and in so far differs from Saxifragece, this therefore, as an intermediate genus, appertaining more to the one in its reproductive organs and to the other in habit, establishes a close relationship between the two.

Essential Character. Polypetalous : stamens fewer than 20 : ovary wholly superior; of several combined carpels with more than one placentae : leaves with stipulary fringes, circinate when young, dotless.

Geographical Distribution. The whole order, with I believe only one exception, are natives of wet and marshy soil, and are found in every part of the world where bogs and marshes occur. In this country we find the Drosera Burmnnni occupying a range of elevation, varying from that of the level of the sea, to 8000 feet. I have gathered it on the banks of the Adyar in Madras, and in the marshes of Ootacamund on the Neilgherries : Drosera Indica has nearly