1656

ARBORETUM AND FRUTICETUM.

PART HI.

high rocky places between Canada and Virginia, andabout the western lakes; where it forms a tree from70 ft. to 80 ft. high. ( Pursh .) When introduced isuncertain; the P. laevigata of Aiton, which is oftenconfounded with this plant, and of which there areplants in the Horticultural Society’s Garden and inLoddiges’s arboretum, being a variety of P. tremula.

It flowers in March and April. According to Michaux,the trunk of the Canadian poplar is furrowed, evenin its old age, as well as on its young branches. It isremarkably hardy, growing in the Atlantic states, onthe river Missouri , 1500 miles from its confluencewith the Mississippi ; while the Carolina poplar ( P.angulata), which is often confounded with it, is notfound above 100 miles from the confluence of the two rivers; and itsannual shoots are frozen, both there and in Europe , by a degree of coldthat does not appear to have the least effect on those of P. canadensis.In Britain, the Canadian poplar used to be very commonly propagated innurseries, and extensively introduced into plantations; but, within the last30 years, the black Italian poplar ( P. monillfera) has been substituted for it.Bose says that the Canadian poplar approaches nearer to P. nigra thanany other species, and that it is the best of all poplars for planting, wherethe production of timber, with a view to profit, is the object. This cor-responds perfectly with the character of P. monillfera in this country,which we suppose to be an improved variety of P. canadensis. Thenatural uses of the tree are the same as those of P. nigra; the young shootsbeing given to horses, as their food, on the banks of the Missouri ; and thebranches being eaten by beavers. The Canadian poplar is propagated bycuttings of the young wood, about 18 in. long, put in during autumn. “ It isremarkable,” Bose observes, “ that the first shoots produced from thesecuttings are always curved at the lower extremity; though in a few yearsthis curvature entirely disappears. The same thing,” he says, “ takes placewith the cuttings of P. monillfera.” The fine poplar avenues in the lowerparts of the gardens of Versailles are formed of this species.

Statistics. In England, in the environs of London , at Mount Grove, Hampstead, 14 years planted,it is 30 ft. high ; in Surrey , at Walton upon Thames, 42 years planted, it is 110 ft. high, the diameterof the trunk 3 ft. 8 in., and of the head 60 ft.; in Worcestershire , at Hadzor House, 22 years planted,it is 55 ft. high. In Scotland, near Edinburgh , at Gogar House, it is 100 ft. high, the diameter otthe trunk 2 ft. 5 in., and of the head 30 ft. In Ireland, near Dublin , in the Cullenswood Nursery,10 years planted, it is 50 ft. high ; in Fermanagh , at Florence Court, 30 years planted, it is 70y-high. In Belgium, at Ghent, in the Botanic Garden, it is 100 ft. high. In Saxony , at Worhtz,60 years old, it is 60 ft. high, with a trunk It ft. in diameter. In Bavaria , in the Botanic Garden,Munich, 81 years old, it is 60 ft. high, with a trunk 18 in. in diameter. In Austria, at Vienna ,in the University Botanic Garden, 60 years old, it is 48 ft. high, the diameter of the trunk

17 in., and or the head 24 ft. ; in Rosenthal’s Nursery, 20 years planted, it is 53 ft. high, the diameter

of the trunk If ft., and of the head 22 ft. ; at Briick on the Leytha, 40 years old, it is 7U ft.high, mediameter of the trunk 3 ft., and of the head 36 ft.

Commercial Statistics. Price of plants, in the London nurseries, 5s. perhundred; or single plants, of some height, Is. each; at Bollwyller, 1| franceach; at New York , 25cents.

i 9. P. (n.) retulifo'lia Pursh. The Birch-leaved Poplar .

Identification. Pursh FI. Amer. Sept., 2. p. 619. ; Spreng. Syst. Veg., 2. p. 244. . « 0

Synonymes. P. nigra Michx. FI. Amer. Bor., 2. p. 244.; P. hudsonica Michx. Arb., 3. p._29u- }■ ■f. 1., North Amer. Syl., 2. p. 230.; P. hudsoni&na Bose, and Lodd. Cat., ed. 1836) American waPoplar , Amer. j Peuplier de la Baie d’Hudson, Fr.

The Sexes. It is uncertain whether it is the male or female plant that is in European collections.Engravings. Michx, Arb., 3. t. 10. f. 1. j Michx. N. Amer. Syl., 2. t. 96. f. 1. j and out fig. ioio.

Spec. Char., §c. Young branches yellow. Branchlets hairy when young. P®"tioles yellow, and also hairy when young. Disk of leaf rhomboid, but mucacuminated; toothed in every part of the edge; hairy on the under sur-face when young, but afterwards glabrous. {Pursh.) The catkins are4 in. to 5 in. long, and destitute of the hairs which surround those of sever ^.-other species. {Michx. jun.) A tree, growing to the height of 30 it.