822 ARBORETUM ET FRUTICETUM BRITANNICUM. 



Flowers brown ; March and April. Seeds ripe ; May. Decaying leaves 



dark brown or black. 

 Varieties. 



*t P. t. 2 pendula. P. pendula Lodd. Cat. 1836 ; P. supina Lodd. Cat. 

 ed. 1836. (The plate of this variety in our first edition, vol. vii. ) The 

 only distinct variety of P. tremula that exists in the neighbourhood of 

 London. 



3 P. /. 3 Itevigdta. P. laevigata Ait. Hort. Kew., Lodd. Cat. ed. 1836. 

 Leaves shining, rather larger than in the species. 



A rapid-growing tree, rather exceeding the middle size, with a straight clean 

 trunk, tall in proportion to its thickness ; and a smooth bark, which becomes 

 grey, and cracks with age. The branches, which extend horizontally, and 

 are not very numerous, at length become pendulous. The young shoots are 

 tough, pliant, and of a reddish colour ; and both the wood and the leaves vary 

 exceedingly, according to the dryness or moisture of the soil in which the 

 tree is grown. The young shoots and leaves, produced in the form of suckers 

 from the roots, are greedily eaten by cattle and sheep. The roots, from their 

 nearness to the surface, impoverish the land, and prevent anything else from 

 growing on it luxuriantly; and the leaves destroy 

 the grass. The wood weighs, when green, 54 Ib. 

 6 oz. ; half-dry, 40 Ib. 8 oz. ; and quite dry, 34 Ib. 

 1 oz. : it consequently loses two fifths of its weight 

 by drying. It shrinks by this operation one sixth 

 part of its bulk, and cracks and splits in an extreme 

 degree. The wood is white and tender : and it is 

 employed by turners ; by coopers, for herring casks, 

 milk-pails, &c. ; by sculptors and engravers ; and 

 by joiners and cabinet-makers ; and for various 

 minor uses, such as clogs, butchers' trays, pack- 

 saddles, &c. As the roots of this tree chiefly 

 extend close under the surface of the ground, it is 

 better adapted for soils that are constantly wet 

 below, than almost any other tree, since its roots, 

 by keeping so very near the surface, are never out 

 of the reach of the air, which they would be if they penetrated into soil 

 perpetually saturated with water. Propagated by cuttings, but not so readily as 

 most other species. Wherever trees are found, they generally throw up suckers 

 from which plants may be selected ; or cuttings of the roots may be made use of. 



t 4. P. (T.) TRE'PIDA Willd. The North American tremblmg-kc.ved 

 Poplar, or American Aspen. 



Identification. Willd. Sp. PL, 4. p. 803. ; Pursh Fl. Amer. Sept., 2. 



p. 618. 

 Synonyme. P. tremuloldes Michx. North Amer. Sylva 2. p. 241., N. 



Du Ham. 2. p. 184. 

 The Sexes. A plant of the female is in the London Horticultural 



Society's arboretum, where it flowered in April, 1835, though only 



5 or 6 feet high. The stigmas were 6 or 8. 

 Engravings. N. Du Ham., 2. t. 53. ; Michx. North Amer. Sylva, 2. 



t. 99. f. 1.; andour^g. 1495. 



Spec. Char., fyc. Disk of leaf suborbiculate, except 

 having an abruptly acuminate point; toothed; having 

 two glands at its base on the upper surface ; silky 

 while young, afterwards glabrous. Bud resinous. 

 Petiole compressed. Disk of leaf toothed with 

 hooked teeth, ciliate. Catkins silky. (Mich.) A 

 tree. Canada to Carolina, in swamps ; and found 

 also from Hudson's Bay to the northward of the 

 Great Slave Lake, as far as lat. 64. Height 20 ft. 

 to 30ft. Introduced in 1812. Flowers brown; 

 April. Seed ripe in May. Decaying leaves dark 

 brown or black. 



