1694- 



ARBORETUM AND FRUTICETUM. 



PART III. 



in one season. The duration of the l)irch is not great, the tree attaining 

 maturity, i" good soils, in from forty to fifty years; but, according to Ilartig, 

 seldom lasting in health till it attains a hundred years. 



Gcograp/ii/. The coimnon birch is a native of the colder regions of the 

 old Continent ; and also, as we think (under the form of B. /jopulifolia, 

 and other kinds, treated by botanists as s[)ecies), throughout great part of 

 North America. It is found in Asia, in Siberia, as far as the Altaic iMoun- 

 tains ; and also in the Himalayas; but not in Africa. According to I'allas, the 

 birch is more common than any other tree, throughout the whole of the Rus- 

 sian empire; being found in every wood and grove, from the Baltic .Sea to the 

 Eastern Ocean; prospering best in a moist alluvial soil (//iiinoso-limosuni) ; 

 and, as it loves a moderate humidity, it always indicates land fit for the plough. 

 In some parts of Russia, innnense tracts are covered w ith this tree alone. In 

 the neighbourhood of Moscow, it forms the prevailing tree in all the woods 

 belonging to the country residences of the nobles, and it may be seen in the 

 foreground of^g. lobl., which is a view of the Lake of Petrovskoye, which, in 



ISl-l, when we made the sketch, was one of the most celebrated " English 

 pleasure-grounds " in that part of the Russian empire. In Europe, Dr. Agardh 

 observes, the region of the birch is bouniled only by vegetation itself. It 

 is found from Iceland to iNIount Etna : in the Icelandic forests its limits are 

 only those of vegetation ; but on Mount Etna it is not higher than 5600 ft. 

 above the level of the sea, its range being about 1 000 ft. It is found on the 

 whole line of the Apennines, in the kingdom of Naples, (where it commences 

 at the height of 4761 ft. above the level of the sea,) and at the height of 

 6100 ft. forms little woods. (Cow/). Bot. Mfg., 1. p. 91.) It is also found on 

 most of the high mountains of the south of Europe ; on Mount Caucasus, 

 in Bucharia, on the eastern shores of the Caspian Sea ; in Kamtschatka, 

 in forests at lat. 5H° n. ; in Dahuria, in Japan, and in West Greenland. (Dec.) 

 Von Buch considers the birch to require a mean temperature of about 

 26°of Fahr. In Lapland, according to the same author, the line of birches is 

 1937 ft. below the line of eternal snow, and 802 ft. above the boundary of the 

 Scotch pine. At Hospcrdet, in a bay of the Icy Sea, the common birch is a low 

 bush; but at Alten it becomes a lofty tree, forming woods. (Schouni in Gnrd. 

 Mag., vol. xii. p. 60.) On the Alps, in Switzerland, it is never found at above 

 the height of 4400 ft. (M. Alphomr Dc Candolle in Gard. Mag., vol. xii. p. 234.) 

 B. alba appears in North America under the form of B. /jopulifolia, which, 

 though by many botanists considered as a distinct species, yet we cannot help 

 thinking is nothing more than a very distinct variety of the birch of Europe. 

 (See No. 2.) B. pumila and B. glandulosa, also found in North America, arc, 

 probably, nothing more than varieties of B. alba. In Britain and Ireland, it 

 IS found abnost every where on mountains and in poor sandy soils ; reaching 



