CHAP. CIII. SALICA X CE/E. PO'PULUS. 164-9 



Propagation, #c. The trembling poplar may be propagated by cuttings, 

 but not so readily as most other species. Wherever trees are found, they 

 generally throw up suckers from which plants may be selected ; or cuttings of 

 the roots may be made use of. In some situations, seedling trembling poplars 

 are abundant in the woods ; and these are sometimes collected by the country 

 people, 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 as 

 they drop, and immediately sown on light, rich, moist soil, and covered with 

 the same soil as slightly as possible, and shaded by branches, spray, leaves, or 

 mats. The plants will come up at the end of four or five weeks, and will 

 grow 1 in. or 2 in. the first summer. In the future culture of the tree very 

 little or no care is required, at least in Britain. On the Continent, and 

 particularly 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 7'en- 

 thredfnidae. These are collected in the beginning of summer, by order of the 

 public authorities ; and payments are made to the collectors in proportion to 

 the quantity they bring in. The Tipula juniperina L. lays its eggs in the 

 leaves and leaf-stalks of this species ; in consequence of which circumstance, 

 red glandular substances, about the size of a pea, are produced : but the 

 injury 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 years 

 planted, is 20 ft. high, in sandy soil ; at Syon, the species, 70ft. 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 head 

 44 ft; in Staffordshire, atTrentham, 10 years planted, it is 30ft. high ; in Yorkshire, at Castle Howard, 

 it is 130 ft. high, the diameter of the trunk 3$ ft. In Scotland, in Renfrewshire, at Bothwell Ca.stlc, 

 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 by 

 the branches 60 ft. ; in Forfarshire, at Courtachy Castle, 14 years planted, it is 40 ft. high ; in Perth, 

 shire, at Taymouth, it is 80 ft. high, diameter of the trunk 2 ft. Sin., and of the head 20 ft. ; in Stirling- 

 shire, at Callendar Park, 10 years planted, it is 30ft. high. In Ireland, in the Glasnevin Botanic 

 Garden, 20 years planted, it is 30 ft. high ; in Gahvay, at Coole, it is 70 ft. high, and the diameter of 

 the trunk is 2 ft. ; in Louth, at Oriel Temple, 40 years old, it is 72 ft. high. In Saxony, at Worlitz, 

 60 years old, it is 40ft. high, the diameter of the trunk 3ft. In Austria, at Vienna, at Briick on 

 the 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 the 

 trunk 10 in., and of the head 15 ft. In Russia, near St. Petersburg, 90 years old, it has a trunk 

 1 ft. in diameter. In Italy, in Lombardy, at Monza, 24 years old, it is 70 ft. high, the diameter of the 

 trunk JA 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 of 

 P. alba , and this is the case also on the Continent. 



4. P. (T.) TRE'PIDA Willd. The Nortli American trembling-leaved 

 Poplar, or American Aspen. 



Identification. Willd. Sp. PL, 4. p. 803. ; Pursh Fl. Amer. Sept., 2. p. 618. ; Spreng. Syst Veg., 2. 



p. 244. 

 Synonyme. P. tremuloldes Michx. Fl. Bar. Amer.,2. p. 243., Mich*. North Amer. Sulva., 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 it 



flowered 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., %c. 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, and 

 silky on both surfaces when young ; glabrous when adult. Petiole very 

 long, 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 in 

 North America, in extensive swamps, from Canada to Carolina; and found, 

 also, from Hudson's Bay to the northward of the Great Slave Lake, as far 

 as lat. 6-t. It was introduced into Britain in 1812, and flowers in April. 

 Its usual period of leafing, in England, is before that off. tremula. There 

 is a plant of this kind in the London Horticultural Society's Garden, which, 

 in 183-i, after being eight years planted, was 12ft. high. On April 20. 1835, 



5P 2 



