Page images
PDF
EPUB
[ocr errors]

tinge of their anthers, and from their being produced very early in spring, when the trees are leafless, and when flowers are particularly valuable from their rarity. The catkins are also, in most species, so numerous, that the effect of the mass of red, when the tree is seen from a little distance, and in a strong light, is very striking. The colour of the anthers of some of the species is so deep, and their size is so large, that a correspondent of the Magazine 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 of cottony down; which, when ripe, and the seeds are shed, adheres to every object near it; and is so like cotton wool in appearance and quality, that it has been manufactured into cloth and paper, though it has been found deficient in elasticity. The buds of P. balsamífera, and all its allied species, are covered with a viscid matter, which is said to be of use in medicine. P. álba, P. (a.) canescens, and their varieties, are easily distinguishable from all the other species, even at a considerable distance, when their leaves are ruffled by the wind, from the thick white cottony down which covers their under surface. The tremulous motion of the leaves, which is common, in a greater or less degree, to all the poplars, proceeds from the great length of the petioles, in proportion to the size and weight of the leaves to which they are attached. Pliny speaks of three kinds of poplar : the black, the white, and the poplar of Libya. He mentions that the poplar was cultivated as a prop to the vine (Plin. lib. xvi. cap. 23. and cap. 37.); and that the trees were planted in quincunx, in order that they might obtain more light and 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 indents the soft wood, without piercing or cracking it. The poplar buckler thus 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 the young shoots with the leaves on during summer, and laid them by, to serve 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 facility with which it is scoured; and, also, from the difficulty with which it catches fire, and the slowness with which it burns. In these respects, it is the very reverse of deal. Poplar, like other soft woods, is generally considered not durable; but this is only the case when it is exposed to the external atmosphere, or to water; and hence the old distich, said to be inscribed on a poplar plank,

“ 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 of the poplar is, that it will thrive in towns in the closest situations; and another is, that, from the rapidity of its growth, it forms a screen for shutting out objects, and affords shelter and shade sooner than any other tree. The females of several of the exotic kinds of poplar have never been introduced into Britain; and, consequently, little opportunity has been found for raising new varieties from seeds; but all the kinds, whether indigenous or foreign, are readily propagated by cuttings or layers, and some of them by suckers. They all like a moist soil, particularly when it is near a running stream; but none of them thrive in marshy or undried soil, as is commonly supposed. On very dry ground, the leaves of the poplar grow yellow, and fall ott' much sooner than when they are planted in a more congenial situation ; but the timber, in dry soils, is said to be more compact, fine-grained, and durable. P. álba and its varieties produce their leaves much earlier than P. nìgra and its varieties. The species and varieties belonging to this genus are in a state of confusion,

from which it will be impossible entirely to extricate them, till both the male and female plants of each sort have been cultivated together for a number of years in the same garden. Judging from the plants in the London nurseries, and in the arboretums of the Horticultural Society and Messrs. Loddiges, we think that all the kinds now in actual cultivation in Britain may be included under the heads of P. álba, P. trémula, P. nìgra, and P. balsamifera.

Poplars, from their rapid growth and great bulk, are liable to have their branches broken off by the wind; in which case, if care is not taken to protect the wound from the weather, the water enters, and the trunk soon rots and becomes the prey, of insects, which in their turn are fed on by birds. The larvæ of a number of moths live on the leaves of the poplars, such as Tórtrix populàna, Bómbyx pópuli, Cerùra vinula, Smerinthus pópuli, S. ocellàtus (the eyed hawk moth), Anacampsis populélla, and a number of others, some of which will be noticed under particular species. The larvæ of Cóssus Ligniperda (see p. 1386.), of Ægèria crabronifórmis (see Mag. Nat. Hist., iv. 445.), and of some others, live on the wood. The larva of the puss moth (Cerùra vínula) is one of the few caterpillars that are known to have the voluntary power of communicating electricity. An'; interesting account of the manner in which this was discovered by a naturalist in Selkirkshire, is given in the Magazine of Natural History, vol. iv. p. 281. The larva of this insect is very common on poplars and willows in Switzerland, where the pupa often remains two full years, before it assumes the perfect state. (Ibid., viii

. 558.) Pópulus græ'ca affords food to this moth, to the poplar hawk moth (Smerinthus pópuli), to the kitten moth (Cerùra fúrcula), to the pebble prominent moth (Notodonta ziczac), and to various species of Clostera, (the

chocolate-tipped moths), which feed exclusively on the poplar and willow. The larva of Smerinthus pópuli (Mag. Nat. Hist., viii. 629.) is very common both on poplars and willows, and often strips them entirely of their foliage; the moth of this species is seldom seen, as it flies but little, and only during the night. The larva of Smerinthus ocellatus is common on willows and poplars froin July to the end of September, and the fly does not usually appear till the following spring. It is stated of this insect, that a female produced young without having any connexion with the male; from which it would appear that in certain Lepidóptera a single pairing can render fertile more than one generation, as well as in the case of the A'phides. (Mag. Nat, Hist., viii. 557.) Trochilium apifórme (the hornet hawk moth) and Agèria asiliformis feed on the Lombardy poplar, on which the larva may be found in May and June, early in the morning; the fly almost invariably mounts to the top of the trees soon after sunrise. (ibid., p. 555.) The splendid European butterfly (not yet detected in Great Britain), Limenitis pópuli

, frequents the aspen. The caterpillar, also, of the fine Camberwell beauty, or, as it used to be called, the poplar butterfly, feeds on the poplar. Both poplars and willows, when the trunks begin to decay, are attacked by the jet ant (Formica fuliginosa), more especially in France, and on this insect that very shy bird, the hoopoe chiefly lives. Among the coleopterous insects, Rhynchites pópuli, Chrysomela pópuli and C. trémulæ, Sapérda popúlnea, and Orchestes pópuli, one of the flea weevils, feed on the leaves of poplars. Notices of all the preceding insects, and of various others which attack the poplar and the willow, will be found in the Magazine of Natural History, vols. i. to ix. inclusive. Various epiphytical fungi are found on the poplar, some of them on the leaves, and others on the bark of the branches or trunk; such as Sclerotium popùlinum Pers., Erysiphe adúnca Link and E. pópuli Link, Erineum aureum Pers., Urèdo populina Pers., and U, ovàta Straus. Some others will be noticed under particular species; and the greater part are included among the Cryptogàmia of our Encyclopædia of Plants, where several of the species are figured.

* 1. P. AʼLBA L. The white Poplar, or Abele Tree. Identification. Lin. Sp., 1463.; Willd. Sp. Pl., 4. p. 802. ; Smith Eng. Bot., t. 1618. ; Eng. Fl., 4.

P: 243. ; Hook. Brit. Fl., ed. 2., p. 132. ; Mackay Fl. Hibern., pt. 1. p. 254. ; Raii Syn., 446. ; Ger. Enum., 1486.; Bauh. Hist., 1. p. 2. fig. 160. Synonymes. P. alba latifolia Lob. Ic., 2. p. 193. fig. 1.; Pópulus No. 1634. Hall. Hist., 2. p. 303. ; P. màjor Mia. Dict., 8. No. 4.; P. nívea Willd. Årb., 297. ; P. álba nívea Mart. Mill.' The name

of Leukē, given to this species by Dioscorides, is still used among the modern Greeks. (See Smith Prod., Sibih. Fl. Græca.) The great white Poplar, great Aspen, Dutch Beech; Peuplier blanc, Ypréau, Blanc de Hollande, Franc Picard, Fr.; Aubo, or Aoubero, in some provinces; weisse

Pappel, Silber Pappel, weissé Aspe, Weissalber Baum, Ger. ; Abeelboom, Dutch. Derivation. The specific name of White applies to the under surface of the leaves, which, when

quivering in the wind, give the tree a peculiarly white appearance. The English name of Abele is derived from the Dutch name of the tree, Abeel; and this name is supposed by some to be taken from that of the city of Arbela, in the plains of Nineveh, near which, on the banks of the Tigris and Euphrates, great numbers of these trees grew. It is said to be the same tree as that mentioned in the Bible as Abel-shittim, Chittim, Shittim-wood, and Kittim. The Dutch Beech is an old name, given to this tree, as we are informed by Hartlib, in his Compleat Husbandman (1659), on account of ten thousand trees of it having been brought over all at once from Flanders, and planted in the country places; where the people, not knowing what they were, called them Dutch beech trees. The French name of Ypréau alludes to the tree being found in great abundance near the

town of Ypres. Engravings. Eng. Bot., t. 1618. ; Ger. Em., 1488.; Bauh. Hist., 1. p. 160.; Matth. Valg., 1. p. 123.

fig. ; Cam. Epit., 65. fig. ; Dod. Pempt., 835. fig.; Dalech. Hist., 86. fig. ; Hayne Abbild., t. 202.; our

fig. 1507. : and the plate of this tree in our last Volume. The Sexes. Both sexes are described in the English Flera, and are not unfrequent in plantations

Trees of both are in the Horticultural Society's Garden.
Spec. Char., 8c. Leaves lobed and toothed ; some-

1507 what heart-shaped at the base; snow-white, and densely downy beneath. Catkins of the female plant ovate. Stigmas 4. (Smith Eng. Fl.) Root creeping, and producing numerous suckers. Branches very white, and densely downy when young. Leaves angular, and generally with three principal lobes, variously and unequally toothed, blunt-pointed, veiny; dark green and smooth above, and covered with a thick remarkably white down beneath. The leaves vary very much in form; and 'on young luxuriant branches they are almost palmate. The tree is a native of most parts of Europe, and is usually found in woods or thickets, in rather moist

soil. It grows to the height of 80 ft. or 90 ft., and flowers in March. Varieties. These are numerous, but the principal one, P. (a.) canescens,

being generally considered as a species, we shall first give it as such; and next enumerate the varieties which belong to it and to P. álba.

¥ 2. P. (A.) CANE'SCENS Smith. The grey, or common white, Poplar. Identification. Smith Fl. Brit., p. 1080. ; Eng. Bot., t. 1619. ; Eng. F1., 4. p. 243. ; Willd. Sp. Pl.,

4. p. 802. ; Michx. North Amer. Sylva, 2. p. 245. t. 100. Synonymes. P. álba Mill. Dict., ed. 8., No. 1., Willd. Arb., 227. ; P. álba foliis minoribus Raii

Syn., 446., Ger. Em., 148. fig., Lob. Ic., 2. 193. fig.; P. álba folio mindre Bauh. Hist., v. 1. p. 2. 16o. fig. ; P. No. 1634. ß Hall. Hist., 2. 303. ; Peuplier grisaille, Fr. The Seres. Only the female plant is expressly described in the English Flora. The plant in the

Horticultural Society's Garden is the male. Engravings. Eng. Bot., t. 1619.; Michx. North Amer. Sylva, t. 100. ; Hayne Abbild., t. 201. ; N.

Du Ham., 2. fig. 52., as P. álba; and our fig. 1508. Spec. Char., &c. Leaves roundish, deeply waved, toothed; hoary and downy

beneath. Catkins of the female plant cylindrical. Stigmas 8. (Smith in Eng. Fl.) It is essentially distinguished from P. álba, as Mr. Crowe first discovered, by the stigmas, which are 8, spreading in two opposite directions. The bracteas of the fertile flowers are, also, more deeply and regularly cut. The branches are more upright and compact. The leaves are rounder, more conspicuously 3-ribbed, and less deeply or acutely lobed. They are downy beneath ; but the down is chiefly greyish, and not so white or cottony as in P. álba: in some instances the leaves are glabrous. (Smith.) 'Smith has described the root as creeping as extensively as that of P. álba. P.canescens is found wild in “wet ground in England, France, and Germany; sometimes also on open elevated spots, where the soil is loamy." (Smith in Rees's Cycl.). It grows to about the same height as P. álba, and Howers in March. “ Mr. Crowe was very instrumental in bringing this tree into notice in Norfolk. He observed it to be of slower growth than P. álba. The wood, though till lately it was but little used or distinguished, is much firmer than that of any other British poplar ; making as good floors as the best Norway fir in appearance; having, moreover, the valuable pro

[graphic]

perty that it will not, like any resinous wood, readily take fire.” (Smith in

Eng. Fl.) Varieties referable to one or other of the preceding kinds, most of them to P. álba. 1 P. a. 2 hýbrida Bieb. Fl.Taur. Cauc., 2. p. 423., and Suppl., p. 633.; P.

álba Bieb., 1.c.;? P. intermèdia Mertens ; P. a. crassifolia Mertens ; and P. grisea Lodd. Cat., 1836; appears to be intermediate between P. álba and P. (a.) canescens. It is plentiful in the neighbourhood of streams in Tauria and Caucasus; whence it appears to have been introduced into Britain in 1816. There is a female plant of this kind in the Horticultural Society's Garden, and young plants in

Loddiges's arboretum. * P.a.3 acerifolia; P.acerifòlia Lodd.Cat., ed. 1836; P. quercifòlia Hort.;

P. palmăta Hort.; is a very distinct variety of P. álba, with the

leaves broad, and deeply lobed, like those of some kinds of A'cer. * P. a. 4 arembérgica, P. arembérgica Lodd. Cat., 1836, seems identical

with P. (a.) acerifòlia; but the plants in Loddiges's collection, which were only received in 1835, are so small, that it is difficult to decide with certainty respecting them. Booth (Gard. Mag., xi.

p. 207.) describes it as growing much more rapidly than the old variety. * P. a. 5 bélgica, P. bélgica Lodd. Cat., ed. 1836, is also a kind removed

from the Continent in 1835; but the plants in Messrs. Loddiges's collection are too small to admit of our stating anything more respecting them, than that they are evidently a variety of P. álba;

probably identical with P. a. acerifolia. * P. a. 6 cáñdicans, P. cándicans Lodd. Cat., ed. 1836, is a strong-growing

variety of P. álba; probably also identical with P. acerifolia. This is the P. tomentosa of the Hawick Nursery, and the hoary poplar of the Edinburgh nurseries, where it is propagated by layers, which

make shoots 6 ft. or 8 ft. long the first season. * P.a. 7 nivea, P. nívea Lodd. Cat., differs very little, if at all, from the

preceding variety. * P. a. 8 ægyptiaca Hort., P. a. pállida Hort., the Egyptian white poplar,

is a much weaker-growing plant than any of the preceding varieties; though we have received specimens of this kind from the Hawick Nursery, and seen a tree bearing this name in the Horticultural Society's Garden, we can say very little about it. Messrs. Archibald Dickson and Son, of Hawick, state that it is unfit for planting for forest purposes.

Other Varieties. The late Professor Mertens of Bremen (as M. Fischer of Göttingen informed us in 1835) planted a number of different sorts of poplar on the ramparts of Bremen; and, in 1816, specimens of these were sent to Sir J. E. Smith, which are now in the herbarium

of the Linnean Society. Of these specimens, the most remarkable is * P. a. 9 pendula, P. a. var. gracilis råmis pendentibus Mertens. — The specimens of this va

riety are of both sexes; and we may presume, from the pendent shoots, that it would be a very desirable kind of poplar to have introduced, if it is not already in this country. There is a pendent-branched tree of P. álba in Lincoln's Inn New Square, which might

probably retain its drooping character, if propagated by cuttings or grafting. Description, &c. The white poplar, and its different varieties, form trees from 80 ft. to 100 ft. high, and upwards, generally with a clear trunk to a considerable height, and a spreading head, usually, in full-grown trees, but thinly clothed with foliage. The roots creep under the surface to a considerable distance from the tree, and send up suckers in abundance. The leaves of all the varieties are white underneath; those of P. (a.) canescens least so; and those of P. a. nivea, and P. a. cándicans, so in the greatest degree. The leaves of the largest-growing varieties of the abele tree, are deeply lobed and indented; very dark above, and very white and downy beneath, with footstalks about 1 in. in length. The young shoots have a purplish tinge, and they are covered with a white down, but the bark of the trunk and of the 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 expansion 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 30 ft., or upwards, with a trunk from 6 in. 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, Évelyn 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

1503 a man's wrist, and 17 ft. in height.” Truncheons of the white poplar, 9ft. 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 Forêts, 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 50 ft. in diameter; and, consequently, that 30 or 40 trees would cover an acre with a thick wood in the 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 decaying after they have borne three, or at most four, crops of poles.

Geography. The common grey poplar (P. (a) canéscens) is generally supposed to be a native of Britain, as well as of France and Germany; but the abele tree (P.álba) 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. álba and its varieties ought to be considered as cultivated forms of P. canescens. P.álba and P. (a.) canescens are indigenous to Europe, as far north as 56° or 57°; and they are found throughout the south of Europe, Caucasus, Persia, and Barbary. They grow in most districts of Britain; and a few stunted plants of P. álba are said by M‘Culloch to comprise all the trees in the Island of Lewis. Whether these trees in Lewis belong to P. álba, or P. (a.) canéscens, 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 Blackwall

, 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. álba and P. (a.) canéscens 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 Compleat Husbandman (published in 1659), states that, some years before the time of his writing, there were 10,000

[graphic]
« PreviousContinue »