Page:Illustrations of Indian Botany, Vol. 2.djvu/113

ILLUSTRATIONS OF INDIAN BOTANY.

51 at all and the fruit is then 1-celled : carpels dehiscing at the ventral suture, separating from each other, either from the base upwards, or from the apex downwards. Seeds usually numerous, rarely definite : albumen fleshy. Embryo small, in the midst of the albumen : radicle pointing towards (he hilum."

Much difference of opinion exists on this head, which seems to indicate that the order as now constituted is not a very natural one, and it certainly affords an instance of the difficulty of establishing natural groups according to the floral organs, some of the genera refer- red here having superior, some inferior, or sub inferior flowers and some have two, some three, and some 5-celled ovaries. The seed however are always albumenous. Under Cactene I directed attention to the circumstance of Dr Lindley removing Grossulariae to a considerable distance from that order, on account of its albumenous seed though associating in its floral characters, as an instance of attaching a high value to that character in one instance while in others he assigned it a very secondary one, we have another instance of the same kind here. The genus Parnassm, though differing in having a free one-celled ovary, parietal placentas, and ex- albumenous seed, he places here, on the supposition that its fringed scales are a peculiar development of a hypogynous disk. This view of the nature of these scales may or may not be correct, but if the presence of albumen is to have so much importance attached to it in one instance, ought we so totally to disregard it in another, as to place a plant, differing so materially both in floral and seminal structure, its seed being exalbumenous, in an order the character of which is to have " the embryo in the axis of a fleshy albumen ? My acquaintance with both Saxifrageae and Crassidaceae is limited, but so far as it extends, these two seem to be most nearly allied orders, differing principally in the more or less complete union of the ovary with the calyx, and the number of carpels, points, in which different genera of each order meet, while they equally associate in the structure of their seed.

Between them and Grossulariae, the affinity is small indeed, and is equally remote from Umbelli ferae, to both of which DeCandolle adverts as relations. Between the section Hydrangeae and Philadelpheae, I have already indicated such an affinity as appears to warrant their union, but as my acquaintance with both is slight, I merely suggest the affinity, leaving to those better informed either to unite them, or show that in this supposition I am in error : the fact however of DeCandolle placing Deutzia here, while all other writers associate it with Philadelphus is in favour of my suggestion.

The species of this order are nearly all natives of northern latitudes, and several are found within the arctic circle, most of them are natives of Mountainous tracts in Europe. The following brief extract from Lindley's Natural System of Botany gives a good i lea of their habits and the kind of stations they prefer.

" Little elegant herbaceous plants, usually with white flowers, coespitose leaves, and glandular stems : some of the species have yellow flowers, others have red, but none blue. They are natives of mountainous tracts in Europe and the northern parts of the world, frequently forming the chief beauty of that rich turf which is found near the snow in high Alpine stations. Some grow on rocks and old walls, and in hedge-rows, or near rivulets, or in groves."

Astringency is the predominating peculiarity of the order, whence an American species has received the name of alum root.

Only one genus has yet been met with in Southern India It is one of those having the placenta pendulous from rhe apex of the cell of the ovary. Only two species belong to it, both obscure weeds having neither use nor beauty to recommend them to notice. They abound in sandy soil on the banks of rivers and near the sea coast.

Vahlia nldenlandioid.es. Roxb.

1. A plant, natural size.

2. Flowers side view.

3 Front view of the same, more highly magnified. 4. Anthers back and front view,

5. Ovary cut vertically, showing the pendulous pla= cenia?. covered on all sides with ovules.

6. Cut transversely.

7. Mature capsule.

8. Cut transversely.

9. A leafj magnified,