COMPARATIVE VALUE OF EXOTIC CONIFER.E IX BRITAIN. 221 



other varieties, all very ornamental, especially B. o. atirea, and 

 B. o. elegantissima, which are favourites with all planters. 



The American Arbor-Vit^. 



Thuia gigantea (the Giant Arbor- Yitse). — Habitat, North- 

 West America. Introduced in 1853. In its native habitat it 

 reaches a height of 150 feet, its tall slender foi'm being a striking 

 feature in the landscape along the Columbia River, where the ti'ee 

 attains its gi-eatest dimensions. It is a fast-gi'owing and elegant 

 tree, and perfectly hardy in this country. Both as a timber and 

 ornamental tree, it is worthy of extensive use. It thrives best in 

 a deep rich moist loam, but will grow in most vai'ieties of soil, if 

 not water-logged, and the site is sheltered. This useful tree is, 

 perhaps, best known as Thuia Lobbi, and sometimes as T, 

 Menziesii. 



Thuia occidentalis (the Common American Arbor- Vitse). — 

 Habitat, Canada, and the New England States. Introduced before 

 1597. It grows to a height of 40 to 50 feet, and supplies a useful 

 timber in its native habitat, which is much used for fencing and 

 other out-door purposes, being light and very durable. It is well 

 known and much used as an ornamental tree or large shrub in 

 this country, and is one of the best coniferous hedge plants. It 

 prefers a moist soil, on a cool bottom, on which it thrives admir- 

 ably. There are several fine ornamental varieties of this Arbor- 

 Vitse, all of which should be planted in suitable places by collectors 

 of choice plants. 



The Japanese Arbor-Vit^. 

 Thuiopsis dolabrata (the Hatchet-leaved Thuia). — Introduced 

 in 1853. Habitat, Japan, where it forms, when young, a sj^eci- 

 ally handsome pyramidal tree, and attains a height of 50 to 60 

 feet. As an oi-namental tree in this country it is equalled by few 

 of the exotic conifers, and should be freely introduced, as it is 

 quite hardy, and thrives well in any sheltered position, but prefers 

 a deep moist loamy soil. There are two beautiful varieties, T. d. 

 Icetevirens and T. d. variegata, both of which merit a place among 

 all collections of conifers. 



The Cryptomeria, 



Crypiomeria elegans (the'Elegant Cryptomeria). — Introduced in 

 1861. Habitat, Japan. Height, 30 feet. It is generally too 

 VOL. XII., part II. p 



