CHAP. CIII.

salica'ce®. po'pulus.

1649

Propagation, S,c. The trembling poplar may be propagated by cuttings,but not so readily as most other species. Wherever trees are found, theygenerally throw up suckers from which plants may be selected; or cuttings ofthe roots may be made use of. In some situations, seedling trembling poplarsare abundant in the woods ; and these are sometimes collected by the countrypeople, and sold to the nurserymen. When it is intended to raise the trem-bling poplar from seed artificially, the seeds ought to be gathered as soon asthey drop, and immediately sown on light, rich, moist soil, and covered withthe same soil as slightly as possible, and shaded by branches, spray, leaves, ormats. The plants will come up at the end of four or five weeks, and willgrow 1 in. or 2 in. the first summer. In the future culture of the tree verylittle or no care is required, at least in Britain. On the Continent, andparticularly in Belgium, it is very subject to the attacks of insects, and espe-cially to those of the larvae of different kinds of moths, butterflies, and 7en-thredfnidm. These are collected in the beginning of summer, by order of thepublic authorities; and payments are made to the collectors in proportion tothe quantity they bring in. The Tipula juniperina L. lays its eggs in theleaves and leaf-stalks of this species; in consequence of which circumstance,red glandular substances, about the size of a pea, are produced: but theinjury done by these is trifling, compared with that effected by other insects,which eat away the disk of the leaf.

Statistics. In England, in the environs of London, at Kenwood, Hampstead, P. t. pendula, 8 yearsplanted, is 20 ft. high, in sandy soil; at Syon, the species, 70 ft. high; in the Isle of Jersey, in Saun-ders’s Nursery, 10 years planted, it is 40 ft. high, the diameter of the trunk 14 in., and of the head44 ft.; in Staffordshire, atTrentham, 10 years planted, it is 30 ft. high ; in Yorkshire, at Castle Howard,it is 130 ft. high, the diameter of the trunk 3$ ft. In Scotland, in Renfrewshire, at Bothwell Castle,80 years planted, it is 73 ft high, the diameter of the trunk is 4 ft., and of the head 117 ft.; in Banff-shire, at Gordon Castle, 84 ft. high, the diameter of the trunk 4 ft., and that of the space covered bythe branches 60 ft.; in Forfarshire, at Courtachy Castle, 14 years planted, it is 40 ft. high ; in Perth,fillire, atTaymouth, it is 80 ft. high, diameter of the trunk 2 ft. 3 in., and of the head 20 ft.; in Stirling-shire, at Callendar Park, 10 years planted, it is 30 ft. high. In Ireland, in the Glasnevin BotanicGarden, 20 years planted, it is 30 ft. high ; in Galway, at Code, it is 70 ft. high, and the diameter ofthe trunk is 2 ft. ; in Louth, at Oriel Temple, 40 years old, it is 72 ft. high. In Saxony, at Wbrlitz,60 years old, it is 40 ft. high, the diameter of tire trunk 3 ft. In Austria, at Vienna, at Briick onthe Leytha, 40 years old, it is 48 ft. high, the diameter of the trunk 2|ft., and of the head 36 ft.In Bavaria, at Munich, in the English Garden, 30 years old, it is 40 ft. high, the diameter of thetrunk 10in., and of the head 15 ft. In Russia, near St. Petersburg, 90 years old, it has a trunk1 ft. in diameter. In Italy, in Lombardy, at Monza, 24 years old, it is 70 ft. high, the diameter of thetrunk ft., and of the head 26 ft.

Commercial Statistics. Plants are seldom propagated in the London nur-series ; but, when they are to be found there, the price is similar to that ofP. alba ; and this is the case also on the Continent.

i 4. P. (t.) tre'pida Willd. The North American trembling-Z^uer/Poplar, or American Aspen.

Identification. Willd, Sp. PI., 4. p. 803.; Pursh FI. Amer. Sept., 2. p. 618.; Spreng. Syst. Veg., 2.p. 244.

Synonyme. P. tremuloldes Michx. FI. Bor. Amer., 2. p.243., Michx. North Amer. Sylva., 2. p. 241.t. 99. f. 1., N. Du Ham., 2. p. 184.

The Sexes. A plant of the female is in the London Horticultural Society’s arboretum, where itflowered in April, 1835, though only 5 ft. or 6 ft. high. The stigmas were 6 or 8.

Engravings. N. Du Ham., 2. t. 53.; Michx. Arb., 3. t. 8. f. 1.; Michx. North Amer. Sylva, 2. t. 99.f. 1.; and our fig. 1510.

Spec. Char., 8fc. Disk of leaf suborbiculate, except having an abruptly acumi-■ nate point, toothed, having two glands at its base on the upper surface,silky while young, afterwards glabrous. (Pursh.) Disk of leaf white, andsilky on both surfaces when young; glabrous when adult. Petiole verylong, not compressed. (Willd., from dried specimens.) Bud resinous. Pe-tiole compressed. Disk of leaf toothed with hooked teeth, ciliate. (Spreng.)Catkins silky. (Michaux,jun.) A tree, from 20 ft. to 30 ft. high; found inNorth America, in extensive swamps, from Canada to Carolina; and found,also, from Hudson’s Bay to the northward of the Great Slave Lake, as faras lat. 64°. It was introduced into Britain in 1812, and flowers in April.Its usual period of leafing, in England, is before that of P. tremula. Thereis a plant of this kind in the London Horticultural Society’s Garden, which,in 1834, after being eight years planted, was 12 ft. high. On April 20. 1835,

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