EXPLANATION OF PLATE 72.
- Celatrus paniculala—1. Flowering branch male plant—natural size.
- 2. An expanded flower seen from above.
- 3. The same, the petals removed, but the disk not clearly shown.
- 4. Stamens back and front views.
- 5. Ovary cut vertically, ovules erect.
- 6. ---transversely, 3-celled, with two ovules in each.
- 7. A raceme of fruit—natural size.
- 8. A seed—natural size.
- 9. The same—magnified.
- 10. A seed cut transversely, showing the embryo surrounded by copious albumen.
- 11. Cut vertically, showing the embryo in situ.
- 12. The seed, the testa removed.
- 13. The embryo detached, cotyledons foliaceous.
LIII.—RHAMNEAE.
This like the last is a large order and like it distributed over every part of the world, except perhaps within the Polar circles being found throughout both the temperate, and the torrid zones. It consists for the most part of trees and shrubs, sometimes scandent, often erect, many of them armed with thorns or stipulary prickles. In most the leaves are alternate and in nearly all the flowers are small and inconspicuous, but with varied inflorescence, being axillary and fascicled, or subspicate, racemose or panicled. The fruit is equally variable being drupaceous and indehiscent with a very hard several-celled nut, or capsular and dehiscent, dividing into three valves. They however nearly all agree in having a 4 or 5-cleft calyx with valvate aestivation, small scale-like petals, and the stamens opposite the petals inserted under the edge of a flat disk which fills the whole cavity of the calyx, and covers the ovary : occasionally, as in Rhamnus, the flowers are unisexual, and one or two genera are said to have the ovary inferior.
"Calyx 4-5-cleft; aestivation valvate. Petals distinct, unguiculate, cucullate or convolute, or rarely flat, inserted into the throat of the calyx, sometimes wanting. Stamens definite, opposite the petals. Torus a flat or urceolate disk. Ovarium free or more or less immersed in the disk, or adhering to the tube of the calyx, 2-3-4-celled : ovules solitary, erect. Fruit free or more or less cohering with the calyx, fleshy and indehiscent, or dry and separating in three cocci. Seeds erect. Albumen fleshy, rarely none. Embryo about as long as the seed : radicle short, inferior : cotyledons large, flat.—Trees or shrubs, often thorny. Leaves simple, alternate (or rarely opposite), minutely stipulate."
Affinities. These are somewhat complex as they are considered rather nearly allied to several orders far removed from them according to the arrangement followed here such as Euphorbiacece, Byttnenacece, Rosacea?, &c, but those with which they seem most nearly to associate are the Celastrineae and Ilicineae, with which they were long confounded. From the former they were removed by Brown on account of their valvular, not imbricate, aestivation of the calyx; their stamens opposite, not alternate with, the petals : their indehiscent not capsular fruit, or when capsular septicidal not loculicidal dehiscence. From Ilicineae they are separated by the valvate aestivation of their calyx and by their discoid polypetalous, not monopetalous diskless, flowers. With Pomaceae they agree in the determinate number of cells of the ovary, in their ascending ovules, and alternate leaves. Generally speaking however they are easily distinguished from all these by their minute scale-like petals opposite the stamens, such certainly is the case with all those I have met with in India.
Geographical Distribution. Of the numerous species referred to this order some are found suited to almost every climate, the Arctic and Antarctic circles excepted. Rhamnus catharticus with some others being found extensively distributed through the more northerly countries of Europe, while Rhamnus hirsuta and Wightii are bolh found in the most southerly parts of India within a few degrees of the line—New Holland : North and South America : the Cape of Good Hope and Senegal in Africa : the Eastern Islands and China all claim indigenous species of this extensively distributed order, In India they abound, every jungle being profusely supplied with some species of Zizyphus, and of about 40 genera referred by Meisner to the order, 13 or about one-third of the whole are natives of India, showing how largely it partakes of the tropical character.
