Tsuga is the Japanese name of the Hemlock-tree.
CONSPECTUS OF THE NORTH AMERICAN SPECIES.
Leaves flat, obtuse or emarginate at apex, with stomata only on the lower surface; cones ovoid, oblong or oblong-ovoid. Cones stalked. Cone-scales broad-obovate, about as wide as long, their bracts broad and truncate.1. [T. canadensis] (A). Cone-scales narrow-oval, much longer than wide, their bracts obtusely pointed.2. [T. caroliniana] (A). Cones sessile; cone-scales oval, often abruptly contracted near the middle, their bracts gradually narrowed to an obtuse point.3. [T. heterophylla] (B, F, G). Leaves convex or keeled above, bluntly pointed, with stomata on both surfaces; cones oblong-cylindric, their scales oblong-obovate, longer than broad, much longer than their acuminate short-pointed bracts.4. [T. Mertensiana] (B, F, G).
1. [Tsuga canadensis] Carr. Hemlock.
Leaves, rounded and rarely emarginate at apex, dark yellow-green, lustrous and obscurely grooved especially toward the base on the upper surface, marked on the lower surface by 5 or 6 rows of stomata on each side of the low broad midrib, ⅓′—⅔′ long, about 1/16′ wide, deciduous in their third season from dark orange-colored persistent bases. Flowers: male light yellow; female pale green, with broad bracts coarsely laciniate on the margins and shorter than their scales. Fruit on slender puberulous stalks often ¼′ long, ovoid, acute, ½′—¾′ long, with broad-obovate scales almost as wide as long, and broad truncate bracts slightly laciniate on the margins, opening and gradually losing their seeds during the winter and mostly persistent on the branches until the following spring; seeds 1/16′ long, usually with 2 or 3 large oil-vesicles, nearly half as long as their wings broad at the base and gradually tapering to the rounded apex.
A tree, usually 60°—70°, and occasionally 100° high, with a trunk 2°—4° in diameter, gradually and conspicuously tapering toward the apex, long slender horizontal or pendulous branches, persistent until overshadowed by other trees, and forming a broad-based rather obtuse pyramid, and slender light yellow-brown pubescent branchlets, growing darker during their first winter and glabrous and dark red-brown tinged with purple in their third season. Winter-buds obtuse, light chestnut-brown, slightly puberulous, about 1/16′ long. Bark ½′—¾′ thick, deeply divided into narrow rounded ridges covered with thick closely appressed scales varying from cinnamon-red to gray more or less tinged with purple. Wood light, soft, not strong, brittle, coarse-grained, difficult to work, liable to wind-shake and splinter, not durable when exposed to the air, light brown tinged with red, with thin somewhat darker sapwood; largely manufactured into coarse lumber employed for the outside finish of buildings. The astringent inner bark affords the largest part of the material used in the northeastern states and Canada in tanning leather. From the young branches oil of hemlock is distilled.
Distribution. Scattered through upland forests and often covering the northern slopes of rocky ridges and the steep rocky banks of narrow river-gorges from Nova Scotia to eastern Minnesota (Carleton County), and southward through the northern states to Newcastle County, Delaware, cliffs of Tuckahoe Creek, Queen Anne’s County, Maryland, southern Michigan, southern Indiana (bank of Back Creek near Leesville, Laurence County), southwestern Wisconsin, and along the Appalachian Mountains to northern Georgia, and in northern Alabama; most abundant and frequently an important element of the forest in New England, northern New York, and western Pennsylvania; attaining its largest size near streams on the slopes of the high mountains of North Carolina and Tennessee.
Largely cultivated with numerous seminal varieties as an ornamental tree in the northern states, and in western and central Europe.