The only species of the genus is, I believe, abundant on the dry banks in the bed of the Palar river below Wallajabad.
EXPLANATION OF PLATE 24.
A. 1. Tamarix gallica var Indica. Natural size. 2. Flower opened, showing the imbricated sepals, the petals, stamens, superior ovary, styles, and dilated stigmas. 3. A stamen showing the sagittate form of the anthers. 4. A single flower as it appears on being removed from the branch, the exterior pointed sepal-like leaf in front, the Bractea. 5. Ovary cut transversely, and opened, showing the parietal attachment of the ovules to the base of the carpels. 6. A mature fruit after dehiscence. 7. A seed with its downy tuft. All more or less magnified.
B. 1. Flower of Trichaurus ericoides. 2. Sepals opened, and the petals removed, to show the insertion of the stamens and ovary. 3. A stamen, anther pointed, 4. A seed with its beak. All magnified.
XX.—ELATINEAE.
A small and unimportant order of herbaceous, marsh, plants, found in all the four quarters of the globe. The stems are ramous, the leaves opposite, stipulate, the flowers small, usually aggregated in the axis, hermaphrodite.
Calyx of from 3 to 5 sepals. Petals as many alternate with them. Stamens either equalling the petals or twice as many. Ovarium 3, 4, or 5-celled with as many styles and stigmas, placentae in the axis bearing numerous ovules. Stigmas capitate. Fruit, a capsule, three 5-celled, three 5-valved, dehiscence either septicidal or loculicidal. Seeds numerous. Albumen sparing or wanting. Embryo cylindrical, radicle next the hilum.
Affinities.
These do not appear to me by any means clear. Formerly they were referred to Caryophylleae, thence Cambessides removed them as a distinct order, on account of their ex-albuminous seed, and capitate stigmas, to which loculicidal dehiscence is added. Both however being alike in that respect, that last character, which by the way is not constant, since I find in. at least two species of Bergia the dehiscence septicidal and not loculicidal, can be of little or no value ; unless perhaps as one by which we may keep Bergia distinct as a genus, from Elatine. The exalbuminous seed and capitate stigmas, while they afford very sufficient grounds for separating them from Caryophyllaceae which have a copious mealy albumen with the embryo rolled round it, and linear stigmas, associate the Elatineae with Lythrariae, in which order, Bartling (Ordines Plantarum) has placed them. From these however, it appears to me, their distinctly hypogynous stamens, numerous stigmas, and free ovaries sufficiently remove them. Dr. Lindley places them in an alliance distinguished by having "albumen present in the seeds" along with Lineae, an arrangement, the propriety of which I confess myself unable to perceive, as the albumen in Elatineae is almost if not entirely wanting.
Essential Character.
Polypetalous: stamens fewer than 20: ovary wholly superior; placentas in the axis; styles distinct to the base; calyx imbricated ecalyculate: leaves opposite, furnished with stipules.
Geographical Distribution.
The plants of this small order are found in moist, marshy grounds in all the four quarters of the globe—Elatine and Bergia are found in India. B. verticillata is common about the banks of water courses and rice fields, while B. ammannoides is more commonly seen in moist sandy soil near the banks of rivers, and in rice fields near the sea coast. Elatine ambigua I have only found in the moist soil of half dried tanks in the Tanjore district, where it forms large green patches.
Properties and Uses.
The properties of this order are unknown, if the species possess any. In England Elatine has received the rather questionable name of "water pepper" which seems to indicate the possession of acrid properties, though that seems doubtful as it is no where men-
