1646

ARBORETUM ANO FRUTICETUM.

PART III.

1.503

whether this is not also only a variety of P. tremula, though he hasmade it a species. The specimen is of a female.

The above varieties, we suppose, still exist on the ramparts of Bre-men; cuttings of them might, no doubt, be procured through theFloetbeck Nursery.

¥ P. t. 8 pendula, P. pendula Lodd. Cat., 1836, and the plate of this varietyin our last Volume, is the only distinct variety of P. tremulathat exists in the neighbourhood of London. The handsomestspecimen is at Kenwood, where a male plant, 8 years planted, is20 ft. high.

? P. i .9 supina, P. supina Lodd. Cat., ed. 1836, closely resembles thepreceding sort; and the plant in the Hackney arboretum is so verysmall, that it is difficult to say whether it is really distinct or not.

*£ P. t. 10 Icevigata ; P. laevigata Ait. Hort. Kew., Lodd. Cat., ed. 1836 ;has shining leaves, rather larger than the species.

Description. A rapid-growing tree, rather exceeding the middle size, witha straight clean trunk, tall in proportion to its thickness; and a smooth bark,which becomes grey, and cracks with age. The branches, which extendhorizontally, and are not very numerous, becomependulous as the tree advances in age. Theyoung shoots are tough, pliant, and of a reddishcolour; and both the wood and the leaves vary ex-ceedingly, according to the dryness or moisture ofthe soil in which the tree is grown. The flowersappear in March, before those of any other poplar.

The roots, Sir J. E. Smith observes, creep and emitsuckers; and these, as well as the young branch-lets, are clothed with brown prominent hairs: theyare sometimes hoary, but not cottony. The colouiof the upper surface of the leaves is a fine darkglaucous shining green, and that of the under sur-face of a paier shade. The disk of the leaf has asmall point, and 3 ribs; it is somewhat wavy, andoften shorter than the footstalk; which, being vertically compressed in its upperpart in relation to the plane of the leaf, counteracts the ordinary wavingmotion of the leaf in the wind, and causes it to quiver with the slightestbreeze; whence has arisen the proverbial theme of comparison, the tremblingof an aspen leaf. ( Smith in Eng. FI.') The leaves, says Dr. Johnston of Ber-wick, -are of a fine smooth dark green, with a narrow yellowish edge, more orless fringed with soft hairs, and suspended on flattened stalks; so that

-“ When zephyrs wake,

The aspen’s trembling leaves must shake:”

and, by their friction on one another, they make a constant rustling noise.(Flora of Berwick upon Tweed, vol. i. p. 220.) The tree, when in a suitablesoil, grows with great rapidity during the first thirty years after being planted,attaining, in that time, the height of from 60 ft. to 80 ft.; afterwards, the trunkincreases slowly in thickness, and in 60 or 80 years it begins to decay, and carseldom occupy the ground profitably for a longer period. When cut oveiby the surface, the stool sends up shoots more freely than the white poplarbut much less so than most other trees that stole. The want of shoots fromthe stools, however, is amply made up by the abundance of root suckers.

Geography, History, SfC. The trembling poplar is a native of most parts o'Britain, in wet soils. It is found as far north as Sutherland ; at above 1600 ftabove the level of the sea, in Braemar, in Aberdeenshire ; and, at an elevationof 1500 ft., in the Isle of Mull. It is indigenous to Ireland, in the county oiDublin, and in other places mentioned in Mackay’s Flora Hibcrnica. It iffound, according to Mirbel, in the whole of the south of Europe, Asi:Minor, and Caucasus, and in Lapland to the Frozen Ocean. It is very abun.