194 ENGLISH BOTANY. 



Tliese lines also allude to the fact tluit poplar wood does not endure wlien exposed to 

 moisture or water. The wood of the poplar contains a considerable quantity of 

 moisture. Loudon saj'S that " white poplar weighs, when green, 58 lbs. 3 oz. per 

 cubic foot, and in a dried state, 38 lbs. 7 oz." The wood of the abele is very white, 

 and it is used where whiteness and lightness are essential. It is also readily stained 

 by dyeing materials. It does not readily warp, and is a good material for wooden 

 buildings on farms, and for barn-doors. The cooper also employs it for wooden 

 dishes and casks. In Sweden the leaA'es are eaten by cattle. For ornamental 

 planting, it needs to be placed where large masses of foliage are picturesque. 

 Individual plants, by their great size, injure by comparison the effect of all sur- 

 rounding objects. There is one property it possesses which recommends it in treeless 

 districts, and that is, the rapid way in which it grows. Withering says, that it 

 withstands better than any other tree the prevalence of north-east winds. In the 

 fifth volume of the "Philosophical Transactions" is a paper by the Rev. W. Stone, 

 in which he says that poplar bark is an efficacious remedy for ague. It contains 

 a principle which is called pojpuUne, and which, like the analogous principle in the 

 willows called salicine, is probably the cause of its beneficial action in disease. 

 The bark also contains tannic acid in sufficient quantities to have been used in 

 tanning leather. 



Throughout Great Britain and Ireland noble specimens of this tree are to be found. 

 Some at Lougleat are said to be 100 feet in height, with trunks from three to four feet 

 in diameter, and with forty to sixty feet of clear bole. On the banks of the Thames, 

 between Hampton Court and Chertsey, are several specimens upwards of 100 feet 

 high. Loudon, in his "Arboretum," gives a list of trees in this country and on the 

 Continent, of great height, and of comparatively yonng age. 



The white poplar is easily propagated by means of layers or truncheons. The 

 latter need not be inserted very deeply, because the roots they send forth always 

 originate in those parts of the truncheon nearest the surface. All authorities agree 

 that in cultivation this species bears lopping worse than any other. 



Sub-Species II.— Populus canescens. Sm. 



Plate MCCC. 



lieich. Ic. Fl. Germ, et Helv. Vol. XI. Tab. DCXV. Fig. I27I, and DCXVI. Fig. 1272. 

 " P. liybrida, M. B. and P. Bachofeuii, Wlerzllclci.'" Belch. Ic. 1. c. p. 29, 

 P. alba, var. /3, Bwmf. Fl. Vect. p. 460. 



Young branches and buds thinly cottony, and grey. Leaves of the 

 suckers deltoid-ovate, subcordate, toothed, but not distinctly angu- 

 lated or lobed, at first flocculent pubescent above, afterwards glabrous, 

 always cottony and greyish- white beneath; leaves of the flowering 

 shoots suborbicular or rhombic-orbicular, sinuate-dentate, white be- 

 neath when young, at length glabrous on both sides. Scales of the 

 female catkins sharply toothed or sublaciniate at the apex. Stigmas 

 2- to 4-partite, purplish crimson. 



In moist woods, meadows, &c. Rather rare, but widely distributed 

 over England, and truly wild in the south and east. Not recorded 

 from Scotland or Ireland even as a naturalised plant. 



