CHAP. CHI. 



SALICACEJE. PO PULUS. 



1641 



1.303 



older branches is grey. In the beginning of April, the 

 male catkins, which are generally about 3 in. in length, 

 appear; and, about a week afterwards, the female catkins, 

 which are shorter, come forth : a week after the expan- 

 sion of the flowers of the female catkins, the males drop 

 off; and, in five or six weeks afterwards, the seeds will 

 have ripened and dropped also. The seeds are enclosed 

 in a hairy or cottony covering ; in consequence of which, 

 they are wafted to a great distance by the wind. The 

 growth of all the varieties is extremely rapid ; so that a 

 tree, 10 years planted, in soil moderately good and 

 moist, will attain the height of 30ft., or upwards, with 

 a trunk from Gin. to 9 in. in diameter; as has been the 

 case with several trees in the Horticultural Society's 

 Garden. As a proof of the rapidity of the growth of 

 the abele tree, Evelyn mentions one of these trees at 

 Syon, " which, being lopped in February, 1651, did, by 

 the end of October, 1652, produce branches as big as 

 a man's wrist, and 17ft. in height." Truncheons of the white poplar, Oft. 

 long, planted on the banks of a stream, some yards from the current, had, in 

 12 years, trunks nearly 10 in. in diameter; and had heads in proportion. (Bath 

 Soc. Papers, 1786, vol. iii. p. 90.) The duration of the tree rarely exceeds 

 two centuries ; but, when it is to be cut down for timber, it should be seldom 

 allowed to exceed 50 years' growth, as the heart-wood at that period, on most 

 soils, begins to decay. Mitchell says that, on the banks of rivers, the tree is 

 at its full value in 40 or 50 years ; but that, in dry situations, it will require 

 from 50 to 70 years to mature it. (Dendrologia, &c., p. 51.) In the Dictionnaire 

 des Eaux et Forets, it is stated, that a tree planted in a field, and surrounded 

 by a fence at 25 ft. distance from it on every side, formed by its suckers, in 

 20 years, a circular clump of wood 50ft. in diameter; and, consequently, 

 that 30 or 40 trees would cover an acre with a thick wood in tne same space 

 of time. Hence it follows, that, when the tree is once introduced into woods, 

 especially where the soil is loamy and moist, it forms a perpetual succession 

 of young trees, however frequently these may be cut down. When treated 

 as coppice-wood, the abele is by no means a durable plant ; the stools decay- 

 ing after they have borne three, or at most four, crops of poles. 



Geography. The common grey poplar (P. (a) canescens) is generally sup- 

 posed to be a native of Britain, as well as of France and Germany ; but the 

 abele tfree (P. alba) is thought by some to have been first brought to England 

 from Flanders. This we think highly probable ; and it is favourable to our 

 opinion that P. alba and its varieties ought to be considered as cultivated 

 forms of P. canescens. P. alba and P. (a.) canescens are indigenous to Europe, 

 as far north as 56 or 57 ; and they are found throughout the south of Eu- 

 rope, Caucasus, Persia, and Barbary. They grow in most districts of Britain; 

 and a few stunted plants of P. alba are said by M'Culloch to comprise all the 

 trees in the Island of Lewis. Whether these trees in Lewis belong to P. alba, 

 or P. (a.) cane'scens, may, however, be doubted. Turner, in 1568, says, "the 

 white aspe is plentifull in Germany and Italy;" but that he does not remember 

 to have seen it in England. Gerard, who wrote 30 years after Turner, found 

 the white poplar at Black wall, near London ; at Ovenden, in Essex; and a few 

 other places. Dr. Walker, writing in 1773, says that it is doubtful whether 

 the abele is a native of England ; but that it certainly has the appearance of 

 being indigenous in several parts of Scotland. But it must be recollected 

 that, in his time, P. alba and jr. (a.) canescens were considered as synonymous. 

 He adds, also, that the abele was planted in many places in Scotland about the 

 end of the seventeenth century ; and that it had been afterwards neglected and 

 despised, in consequence of the great number of suckers that it threw up all round 

 it from its creeping roots. Hartlib, in his Complcat Husbandman (published in 

 1659), states that, some years before the time of his writing, there were 10,000 



