a genus of plants belonging to the clas pendandria, in the Linnean arrangement, and to the order digynia. The generic characters are the following: The calyx is monophyllous, quinquifid, acute, small, and permanent. The corolla is monopetalous, flat, large, and divided, deeper than the middle, into five parts, with broad, flat, pointed laciniæ. The stellatum is small, star-shaped, flat, quinquifid, with linear laciniæ; and embracing with its ragged points the feeding parts. Another small star, which is also flat and quinquifid, covers the feminiferous parts with its entire acute laciniæ. The stamina are five in number; the filaments are erect, flat, and broad; and the antheræ are linear, on each side united to the side of the filament. The pistillum has two germina, which are oval and flat on the inside. There are no styles; and the stigmae are obsolete. The seed-vessel consists of two oblong, awl-shaped, unicellular and univalved follicles. The seeds are numerous, imbricated, compressed, and crowned with a papilus or down.

This singular tribe of plants is peculiar to the sandy deserts of Africa and Arabia. They are extremely succulent. From this peculiarity of structure, the power of retaining water to support and nourish them, they are enabled to live during the prevalent droughts of those arid regions. On this account, the stapelia has been compared to the camel; and we are told that, by a very apt similitude, it has been denominated "the camel of the vegetable kingdom." We must confess ourselves quite at a loss to see the propriety or aptitude of this comparison. In many parts of the animal and vegetable economy there is doubtless a very obvious and striking analogy; but this analogy has been often carried too far; much farther than fair experiment and accurate observation will in any degree support. It is perhaps owing to this inaccuracy in observing the peculiarity of structure and diversity of functions, that a resemblance is supposed to exist, as in the present case, where in reality there is none. The camel is provided with a bag or fifth stomach, in addition to the four with which ruminant animals are furnished. This fifth stomach is defined as a reservoir to contain water; and it is sufficiently capacious to receive a quantity of that necessary fluid, equal to the wants of the animal, for many days; and this water, as long as it remains in the fifth stomach, is said to be perfectly pure and unchanged. The stapelia, and other succulent plants, have no such reservoir. The water is equally, or nearly so, diffused through the whole plant. Every vessel and every cell is fully diffused. But besides, this water, whether it be received by the roots, or absorbed from the atmosphere, has probably undergone a complete change, and become, after it has been a short time within the plant, a fluid possessed of very different qualities.

The peculiar economy in the stapelia, and other succulent plants, seems to exist in the absorbent and exhalant systems. The power of absorption is as much increased as the power of the exhalant or peripatatory vessels is diminished. In these plants, a small quantity of nourishment is required. There is no solid part to be formed, no large fruit to be produced. They generally have very small leaves, often are entirely naked; so that taking the whole plant, a small surface only is exposed to the action of light and heat, and consequently a much smaller proportion of water is decomposed than in plants which are much branched and furnished with leaves.

Two species of stapelia only were known at the beginning of the century. The unfortunate Forskål, the companion companion of Niebhur, who was sent out by the king of Denmark to explore the interior of Arabia, and who fell a sacrifice to the pelliciential diseases of those inhospitable regions, discovered two new species. Thunberg, in his Prodromus, has mentioned five more. Forty new species have been discovered by Mr. Maitton of Kew Gardens, who was sent out by his present Majesty for the purpose of collecting plants round the Cape of Good Hope. Descriptions of these, with elegant and highly finished coloured engravings, have lately been published. They are chiefly natives of the extensive deserts called Karroo, on the western side of the Cape.