Illustrations of Indian Botany, Vol. 1/Erythroxyleae

by Robert Wight

XXXV.—ERYTHROXYLEAE.

This is one of the smallest orders of the Indian flora, being at the time we published the Prodromus limited to one Peninsular species, the one here figured, one or two others have since been found on the continent, and one in Ceylon. The species are generally shrubs or small trees, with ascending branches, the young shoots of which are often compressed and covered with acute imbricated scales. The leaves are alternate or rarely opposite, glabrous, with axillary stipules. The flowers are small, axillary, solitary, or several together, whitish or greenish, the peduncles furnished with bracts at the base.

Calyx free, persistent, 5-parted: torus inconspicuous: petals 5, hypogynous, equal, alternate with the lobes of the calyx, broad at the base, and furnished with a plaited scale within, stamens 10, hypogynous, filaments united at the base : anthers erect, 2 celled, cells opening longitudinally by a lateral slit. Ovary 3-celled, two often imperfect or empty, with a solitary pendulous ovule in each: styles 3, distinct, or rarely cohering: stigmas capitate. Fruit drupacious, l-seeded, albumen horny. Embryo linear, straight: radicle superior round, straight. Cotyledons linear, foliaceous.

Affinities. This order was separated from Malpighiaceae by Kunth, on account of the appendages of the petals, the presence of albumen in the seed, the fruit being often 1-celled by abortion, and the peculiar habit. These however in the estimation of Dr. Lindley do not appear peculiarities enough to constitute it more than a subdivision of Malpighiaceae, on which account he has restored it to that family as a suborder. In the propriety of this distribution I am inclined to coincide, though my limited acquaintance with this order, precludes my adopting it.

Geographical Distribution. The West Indies and South America appear to be the head quarters of this order, but some species are found in the Mauritius and Madagascar, and a few (6 or 8) in India. The only species I have met with in Southern India are, the one here figured, and two from Courtallum, I have besides specimens of another from Ceylon, which I named Sethia acuminata, on account of the long acumen which terminates its elliptic oblong leaves.

Properties and Uses. The only notice I find under this head refers to a single South American species, the Erythroxylon coca, of which there is a very detailed account in Hooker's Companion to the Botanical Magazine. According to the writer of that paper, its effects are fully as deleterious as those of opium. The following extract from Lindley's Flora Medica, gives an abbreviated summary of its effects.

"A powerful stimulant of the nervous system, affecting it in a manner analogous to opium. Less violent in its effects than that drug, but more permanent in its action. The Peruvians chew the leaves with finely powdered chalk, and the government of Potosi alone, derived a revenue of as much as 500,000 peso duros in the year 1583, from their consumption."

Remarks on Genera and Species. Two genera only are referred to this order, Erythroxylon and Sethia, and of the last only 3 or 4 species are known. Three are natives of southern India, and one from Ceylon. The continental ones may be thus briefly characterized. S. indica, leaves obovate, cuneate, styles united to the apex—S. lanceolata, leaves lanceolate, cuneate towards the base, styles united two-thirds of their length—S. erythroxyloides, leaves lanceolate, styles free to near the base, short. Dr. Lindley in the second edition of his natural system of Botany, with great propriety, in my opinion, reduces the last of these as being separated on too trivial grounds, the union of the styles, a mark, which I cannot consider of generic value, though, for the sake of preventing unnecessary disturbance of established names, I have here retained it. Mr. Arnott gives the following character of the Ceylon one in his Pugillus Plantarum Ind : Orientalis.

Sethia acuminata, (Arn.) Leaves alternate, elliptic oblong, acute at the base, suddenly acuminated at the point, penninerved, paler beneath, pedicels axillary, about a half longer than the petiols, solitary, 1-flowered, calyx 5-cIeft, segments ovate, acute, the styles cohering almost to the apex, stigmas globose.

Hab.—Ceylon.

My specimens, to which I had previously given the same specific name, accurately correspond with this character.

Sethia lanceolata, (R. W.) Leaves lanceolate, obtuse, short petioled, peduncles axillary, solitary, about thrice the length of the petiols, styles longer than the stamens, united about two-thirds of their length, free, and recurved at the apex, stigmas globose.

Var. ß. obtusifolia. Leaves from elliptical tapering slightly towards the base to obovate, cuneate.

Hab.—Courtallum in thick jungles.

These two varieties are probably distinct species, but as the form of the style and stigmas is the same in both, I prefer keeping them together, though they look different. In the first the leaves are long and narrow in proportion to (heir length, that is, from 2½ to 3 inches long, by about ¾ of an inch in breadth : while in the other they are about H inch in length, and | to 1 inch in breadth, and the siipules which sheath the ends of the young shoots are larger.

Sethia erythroxyloides, (R. W.) Leaves oblong, lanceolate, coriaceous, slightly refuse at the apex, subsessile : peduncles axillary, solitary, three or four times the length of the petiols: styles shorter than the stamens, free, nearly to the base; stigmas recurved, clavate.

Hab.—Courlallum in thick jungles.

This species is very closely allied to the former, but the marked difference in the styles and stigmas forbid their being united.

EXPLANATION OF PLATE 48.

1. Sethia indica, natural size.

2. An expanded flower.

3. The same, partially dissected with a detached petal, showing the scale at the base.

4. The stamens removed to show the union of the filaments.

5. Detached stamens back and front views.

6. The ovary cut transversely, the upper half with the style and stigmas attached.

7. The same cut vertically, showing the pendulous ovary.

8. A mature fruit, natural size.

9. Cut transversely, two of the cells empty.

10. Cut vertically, showing the form of the seed.

Obs.—Owing to an oversight the numbers were not added in this plate, those here given are what ought to have been, and may be yet supplied with pen and ink.

ERYTHROXYLEÆ

SETHIA INDICA.