CHAP. CIII.

■salica'ceae. po'pulus.

1637

tinge of their anthers, and from their being produced very early in spring,when the trees are leafless, and when flowers are particularly valuable fromtheir rarity. The catkins are also, in most species, so numerous, that theeffect of the mass of red, when the tree is seen from a little distance, and in astrong light, is very striking. The colour of the anthers of some of thespecies is so deep, and their size is so large, that a correspondent of theMagazine of Natural History compares them, when torn off by a high wind,and lying on the ground, to “great red caterpillars.” (See vol. vi. p. 198.)The females of all the species have their seeds enveloped in abundance ofcottony down; which, when ripe, and the seeds are shed, adheres to everyobject near it; and is so like cotton wool in appearance and quality, that ithas been manufactured into cloth and paper, though it has been found de-ficient in elasticity. The buds of P. balsamifera, and all its allied species,are covered with a viscid matter, which is said to be of use in medicine. P.alba, P. (a.) canescens, and their varieties, are easily distinguishable from allthe other species, even at a considerable distance, when their leaves areruffled by the wind, from the thick white cottony down which covers theirunder surface. The tremulous motion of the leaves, which is common,in a greater or less degree, to all the poplars, proceeds from the great lengthof the petioles, in proportion to the size and weight of the leaves to whichthey are attached. Pliny speaks of three kinds of poplar: the black, thewhite, and the poplar of Libya. He mentions that the poplar was cultivatedas a prop to the vine (Plin., lib. xvi. cap. 23. and cap. 37.); and that thetrees were planted in quincunx, in order that they might obtain more lightand air. He also says that the wood of the poplar, like that of the willow,and of all the aquatic trees, is particularly suitable for making bucklers,from its lightness; and because, when struck, the blow only indentsthe soft wood, without piercing or cracking it. The poplar bucklerthus acted like a shield of Indian rubber, or any other elastic substance,and repelled the blow. The ancients applied the leaves of the poplar,macerated in vinegar, to parts affected by the gout; and they dried theyoung shoots with the leaves on during summer, and laid them by, toserve as winter food for cattle. The wood of the poplar is soft, light,and generally white, or of a pale yellow. It is but of little use in the arts,except in some departments of cabinet and toy making, and for boarded floors;for which last purpose it is well adapted, from its whiteness, and the facilitywith which it is scoured; and, also, from the difficulty with which it catchesfire, and the slowness with which it burns. In these respects, it is the veryreverse of deal. Poplar, like other soft woods, is generally considered notdurable; but this is only the case when it is exposed to the external atmo-sphere, or to water; and hence the old distich, said to be inscribed on a poplarplank,—

“ Though heart of oak be e’er so stout,

Keep me dry, and I ’ll see him out,”

may be considered as strictly correct. One of the most valuable properties ofthe poplar is, that it will thrive in towns in the closest situations ; and anotheris, that, from the rapidity of its growth, it forms a screen for shutting out ob-jects, and affords shelter and shade sooner than any other tree. The femalesof several of the exotic kinds of poplar have never been introduced intoBritain; and, consequently, little opportunity has been found for raising newvarieties from seeds; but all the kinds, whether indigenous or foreign, arereadily propagated by cuttings or layers, and some of them by suckers. Theyall like a moist soil, particularly when it is near a running stream; but noneof them thrive in marshy or undried soil, as is commonly supposed. On verydry ground, the leaves of the poplar grow yellow, and fall off much sooner thanwhen they are planted in a more congenial situation ; but the timber, in drysoils, is said to be more compact, fine-grained, and durable. P. alba andits varieties produce their leaves much earlier than P. nigra and its varieties.The species and varieties belonging to this genus are in a state of confusion,

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