Page:On the characters, properties, and uses of Eucalyptus globulus and other species of Eucalyptus.djvu/7

 have evergreen leaves, which, like those of certain species of Acacia and other trees that are natives of Australia, usually (after the tree has arrived at a few years of age) hang in an oblique or even vertical direction from the branches, and thus give a very peculiar aspect to the forests of Australia by the difference in the light and shade produced by the trees from those of forests generally in other parts of the world. These leaves are commonly studded with internal glands or receptacles of volatile oil, as may be seen by holding them up to the light, when they present a semitransparent dotted appearance. The flowers, which are usually pinkish or white, are frequently very beautiful, so that this character, combined with the beauty and singularity of their foliage, the elegant appearance generally of the species, and the agreeable nature of their odours, renders them favourite objects for culture. The flowers, when of a white colour, much resemble myrtle-blossoms, but are at once distinguished from them by the absence of petals, and by their peculiar calyx, which in the bud state is closed at the top by a little lid, which is thrown off as the flower expands. The fruit, which consists essentially of the hardened somewhat globular or tubular calyx, contains a number of seeds, which, considering the enormous size and height these trees sometimes attain, over 300 feet in altitude and 100 feet in circumference, are extremely minute. Thus, according to Mueller, one ounce of the seed of the Blue Gum-tree (Eucalyptus globulus) contains over 10,000 seeds, and a similar weight of another species more than double that number; and thus from one pound of seeds of the Eucalyptus globulus nearly 162,000 plants could be raised.

With these general remarks upon the Eucalypti we now pass to the more particular description of Eucalyptus globulus. Several plants of this species now before us, from our new Economic-house, will afford us good illustrations; one of these has been in the gardens some years, and is more than 15 feet high; and the others have been mostly raised from seeds forwarded to this Society by Dr. Richard Schomburgk from Australia.

The Eucalyptus globulus, commonly known as the Blue Gum-tree, is a native of Tasmania, where it is more especially found on the damp slopes of valleys with a southern aspect. The foliage presents in a remarkable degree the changing aspect of the species of Eucalyptus. Thus in young plants the leaves are of large size, sessile, placed horizontally on the stem and branches, and of a bluish glaucous-white colour; but on plants varying from three to five years old the leaves become narrower, of a bluish-green colour, somewhat