The
genus Tsuga - the Hemlocks
A genus of c. 10 species. Leaves flattened, usually arranged in two ranks and attached by short, decurrent stalks. Cones about one inch long, ovoid or oblong, borne in large numbers at the ends of branchlets.
Tsuga canadensis, Carrière
Eastern Hemlock
Native to Eastern North America and one of the hardiest of ornamental trees, attaining 100 feet. Introduced into this country in 1736. It has a pyramidal habit often rather broad- based with horizontal slender branches and pendulous branch- lets. The leaves are lustrous dark green and have two white stomatal lines on the lower sides. Not used for timber planting, it is grown as a decorative tree in this country.
(P)
Tsuga diversifolia, Masters
Japanese Hemlock
A graceful small tree growing up to 80 feet in its native Japan. Introduced into this country in 1861, it has a pyramidal habit with horizontal or slightly ascending branches. The branchlets are reddish brown and slightly pendulous. The leaves are arranged usually in three ranks and are linear-oblong, notched at the apex, lustrous dark green above, and with two silver stomatal bands below.
(A)
Tsuga heterophylla, Sargent
Western Hemlock
Native to the Western North America from California to Alaska and growing to a height of 200 feet. Introduced into this country in 1851. It grows well in the moister parts of the country and forms a large pyramidal ornamental tree with a slender tapered top. It is much used for wood-pulp in America and merits consideration as a timber tree in this country. It withstands shade well.
(T)
Tsuga mertensiana, Carrière (T. Pattoniana Sene.)
Mountain Hemlock
Native to Western North America from California to Alaska and growing to a height of 100 feet. Introduced into this country in 1854, it makes an attractive tree with a dense branch system and shapely habit, but unfortunately grows very slowly. The leaves are somewhat grey-green and the lines of stomata not very conspicuous, but present on both sides of the leaf.