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San Jorge camps are much infested with the Mio mio. Great care had always to be taken with English sheep imported into the country; but even native sheep are not uncommonly poisoned by it, particularly in spring, when the plant is coming up with the young grass. At that season I have lost many lambs and young sheep from eating Mio mio. Mares also are sometimes poisoned. They crop the grass very close to the roots, and thus, I think, eat the Mio mio when it is young and not easily detected. I do not recollect of having lost any cattle by it. As a rule, most animals soon learn to avoid it. The animals affected show symptoms of inflammation; and the stomach and intestines after death are found dreadfully inflamed. You will not be surprised at this when I tell you that Mio mio makes one of the strongest blisters I know. I have often used it, simply mixing the green of the plant with grease, for blistering my horses' legs. I believe the root is even more powerful."

One tree still remains to be noticed, the "Ombú” (Picruna or Phytolacca dioica), which, if not native, has at all events made itself thoroughly at home in Uruguay. It forms a striking exception to the herbs and under shrubs of which its family otherwise consists, for it is a large and stately tree, with a trunk which sometimes attains a girth of 20 or even 30 feet. In one respect, however, its exceptional character is more apparent than real, for, as M. Bory St Vincent remarks, its stem retains so much herbaceous softness that it may be cut like an enormous carrot. He adds,-writing of an avenue of Ombús in the public promenade at Seville,-that, from the form of the leaves and the height of several specimens, they might be taken for poplars. But this is certainly not the character of the tree in Uruguay and Buenos Ayres, where, although attaining a considerable height, it tends rather to breadth then length, and the dense rounded masses of its foliage are more suggestive of the sycamore than the poplar among European trees. Perhaps the tree which it most resembles, as Sir Joseph Hooker remarks of the specimens he saw at Gibraltar, is the Mango. The Ombú seems expressly designed to adorn public parks and avenues in warm climates, for while its soft spongy tissue is quite unfit for burning

or the ordinary utilitarian purposes of a tree, it not only casts a dense and wide shade, but throws out to a distance of several yards buttresses, which are only a foot or two in height and flattened on the upper surface, thus forming natural benches inviting the weary to sit down and rest. Notwithstanding the softness of its wood, it stands wind well, and it is far from being a delicate tree, as in the Banda Orientál it is frequently exposed at night in winter to a temperature several degrees below the freezingpoint.

The native locality of the Ombú is not well ascertained. Buenos Ayres was long supposed to be so, probably because of its introduction thence to Europe; but the fact that it is never found in the open campos of that province, but only near the capital, points to the conclusion that it owes its presence there to the Spaniards, who, it might be expected, would readily promote the cultivation of so shady a tree in those parts of their dominions which, like Buenos Ayres, were naturally destitute of wood. Gaudichaud seems to have thought that it was native near Monte Video, but this also is a locality long in possession of the Spaniards; and it is surely unlikely that such competent observers as D'Orbigny and Darwin should have failed to notice so conspicuous a phenomenon as the occurrence of these splendid trees, as natives, in a locality noted for its poverty of natural wood. Unlike Buenos Ayres, Uruguay can undoubtedly boast of possessing Ombús in the open country, but they are extremely rare. D'Orbigny, Darwin, and Dr Bauermeister do not seem to have met with them at all, and in my journey of 160 miles to San Jorge I saw only two or three groups on unenclosed ground. Each group consisted of two or three trees, apparently of the same age, standing in a formal manner on the top of a conspicuous ridge, so that there could hardly be a doubt that they had been planted, perhaps to serve as landmarks in these monotonous regions. I may add, that all my English friends, from various parts of Uruguay, agreed in saying that they had never seen the Ombú growing in natural groves. It may, however, be native in the north of Uruguay, as we really know almost nothing of that district, and this is the more probable, inasmuch as the province of

Rio Grande in Brazil, which is contiguous with it, is mentioned by Gaudichaud as a native locality of the Ombú. Other, but probably not native, South American localities where it has been met with, are near Rio Janeiro, in Corrientes, where D'Orbigny mentions having seen two very large trees at an Estancia in lat. 28°, and in New Granada. (cultivated). In the hotter parts of Europe it seems to thrive, but it is not nearly so common even in Spain as the long-continued intercourse with its South American colonies would lead us to expect. Azara at the beginning of the century saw only one specimen at Cadiz; and the instance. of Seville, already referred to, is the only one I have met with mentioned in books, of its cultivation by the Spaniards as an avenue tree. It is common in the gardens at Gibraltar. Sir Joseph Hooker describes the Ombús there as very handsome, leafy, rounded, and massy looking trees, having the general aspect of the Mango; and Mr Archer, in a paper read to this Society, says that many of their great gouty stems are 6 feet in diameter at the base, but rapidly diminish to a third of that size at 3 or 4 feet from the ground.

Dr Cleghorn informs me that he has seen this beautiful tree growing at Malta, and that it is also cultivated at Bombay and Calcutta.

A good figure of the leaves, flower, and fruit of the Phytolacca dioica is given in L'Heritier's "Stirpes." The illustration accompanying this paper shows mainly the character of the stem in trees of considerable age. It is taken from a sketch of one of the finest specimens I saw in South America, measuring no less than 32 feet in girth at its narrowest part, 3 feet from the ground, clear of the projecting buttresses, and below its division into branches of very various sizes,-a common but not invariable habit of the Ombú. This noble tree grows on an elevated plateau at Belgrano, near Buenos Ayres. Many others are to be seen in its neighbourhood, and in order to show their general form I have represented two or three, which stand on the edge of the plateau, overlooking the alluvial plain of the Rio de la Plata. In the distance is shown a fringe of poplars and other trees, beyond which lies the river, here not less than 20 miles in width.

XXIV. Notes on the Flora of the Neighbourhood of Blantyre, Shire Highlands, Central Africa. By Mr JOHN BUCHANAN, in a Letter to Professor BALFOUR, dated August 6, 1877.

(Read 13th December 1877.)

The timber here, as in many places among the Shire Hills, is, as a rule, inferior. Beside streams and in damp places some good trees are seen. Except in such places it is rare to meet a tree of more than a foot in diameter. In appearance the trunks resemble much the Plane tree at home. The Lisuka tree is the most useful for house-building and other purposes. The wood is red and hard, and has the advantage of not being soon attacked by insects; the fruit is of a brown colour, about the size of a plum, and much eaten by the natives. It agrees well with the order Santalaceæ, and is plentiful. A wood with a dark, hard centre and yellow alburnum is also plentiful. I have not seen the flower; the leaves are pinnate. A species with white, soft wood and tripinnate leaves is abundant; it is called "Jumbo" by the natives, and from the liber of its bark they make cloth. Acacias abound in both marshy and dry places. There are several species, one has the peculiarity of being flat on the top. A shrubby species is when in flower a complete mass of yellow bloom, giving out a delightful odour. Gum exudes spontaneously from all the species; one kind is very pure and clear, another brown. There are no Tamarind or Baobab trees in the neighbourhood, but thirty miles north they are plentiful. Here and there is a species of Fig tree. Lime trees [?] at one station have cast their foliage twice since November, and are in full foliage now. They are plentiful, but the fruit has never come to maturity. The order Proteacea is well represented. There are many Salicaceous shrubs. The orders Leguminosæ and Compositæ are most numerous in species. There is a vast number of twining Papilionacea; some are so strong and tough that I use them as garden-lines. Next to these orders come Orchidaceæ, Labiatæ, Liliaceæ, and Amaryllidaceae. There are many species of Orchids, both epiphytal and terrestrial. Five of the latter are particularly good—a yellow, a purple, a red,

and two white species. Labiata contain many showy plants, chiefly about waste places. I have seen some lovely specimens of Liliaceæ. Several species of Aloe are found on the hills. We have about 400 plants beautifying our station. The natives brought them for sale; the price was an inch of calico per plant. Some of the Amaryllidacea have very large bulbs; they average 6 inches in diameter. A variety of Castor-oil plant grows profusely about old gardens. The natives extract the oil by boiling the seed, which they use chiefly for lubricating their persons. The orders I have mentioned are the most conspicuous, but many more are represented. I feel confident that there are here many flowering plants which, if brought home and cultivated, would compare favourably with any yet introduced. Ferns as well as flowers are in abundance. At a stream above the station I observed about twelve different species. There are species of Adiantum, Lastrea, Athyrium, Polystichum, Polypodium, and Osmunda. A noble-looking Osmunda, scarcely distinguishable from Osmunda regalis, is in endless quantity. Thrice I have gone Fern-hunting to the mountains, and found quite different forms from those in the streams. A species, apparently Lastrea montana, is everywhere present. Where two or three stones are heaped together, there it appears. I found a remarkable. fern; it is about 4 inches high-frond almost a circle; in many parts about one-eighth of an inch broad. These parts fold slightly in the back, and inclose the spores. I have seen species of Lindsæa, Lomaria, and Pteris. I gathered one species of Moss; there are a few Lichens and Fungi; one edible species of Mushroom is very large. Whilst an outhouse was being levelled I discovered what I presume to be a species of Truffle, of a small size, oval-shaped, skin hard and black. I have seen several fine grasses which, if grown at home, would prove ornamental. The chief crops cultivated by the natives are Indian Corn, Ground Nuts, Beans, Sweet Potatoes, and Pumpkins. There are no Water-Melons in the neighbourhood. Indian Corn is the staple food of the country; from it they make a flour which they call Uffa. The corn being taken off the cobs, is stamped in a stamper with a little water. This finished it is sifted, not through a sieve, but simply shaken until all the flour is shaken out.

TRANS. BOT. SOC. VOL. XIII.

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