Trees to 30m; trunk to 1.5m diam.; crown broadly conic. Bark brownish, scaly and fissured. Twigs yellow-brown, densely pubescent. Buds ovoid, 1.5--2.5mm. Leaves (5--)15--20(--25)mm, mostly appearing 2-ranked, flattened; abaxial surface glaucous, with 2 broad, conspicuous stomatal bands, adaxial surface shiny green (yellow-green); margins minutely dentate, especially toward apex. Seed cones ovoid, 1.5--2.5 ´ 1--1.5cm; scales ovate to cuneate, 8--12 ´ 7--10mm, apex ± round, often projected outward. 2 n =24. Moist rocky ridges, ravines, and hillsides; 600--1800m; N.B., N.S., Ont., P.E.I., Que.; Ala., Conn., Del., Ga., Ind., Ky., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Ohio, Pa., R.I., S.C., Tenn., Vt., Va., W.Va., Wis. Numerous cultivars of Tsuga canadensis have been developed, including compact shrubs, dwarfs, and graceful trees. Wood of the species tends to be brittle and inferior to that of the other North American hemlocks. Eastern hemlock ( Tsuga canadensis ) is the state tree of Pennsylvania.
Tree 22 - 30 m tall, trunk diameter 0.5 - 1.5 m Bark: reddish brown, thick, and deeply furrowed into wide, scaly ridges. Inner bark reddish purple (observed when broken or cut). Twigs: slender, pale brown, and hairy when young, becoming grayish brown and hairless with age. Buds: reddish brown, 1.5 - 2 mm long, and egg-shaped. Form: pyramidal with a drooping topmost shoot. Lower branches often drooping down to the ground. A rounded top is typically found on large, mature trees. Pollen cones: yellowish, about 1 cm long, spherical, near the ends of the branchlets. Needles: on short, thin stalks, shiny green above with two whitish bands beneath, 0.6 - 1.4 cm long, 1 - 2 mm wide, linear, flat, flexible, rounded at the tip, and minutely toothed near the apex. The needles are spirally arranged around the shoot, appearing two-ranked by the twisting of the needle stalks. Young seed cones: pale green, about 3 mm long, cylindrical, near the ends of the branchlets. Pollination between cones occurs in spring. Mature seed cones: woody, short-stalked, hanging down at the ends of twigs, reddish to light brown, 1.3 - 2 cm long, and cylindrical to egg-shaped. Scales thin with rounded, sometimes faintly toothed margins. Seeds light brown, 1 - 3 mm long, triangular, with wings twice as long.
Similar species: Tsuga canadensis is distinguished from other trees in the Pine family by its reddish purple inner bark, its foliage flattened into a single plane, the short, flat, and seemingly two-ranked needles, and its small seed cones. No hemlocks are native to the Chicago Region.
Habitat and ecology: In the Chicago Region, Tsuga canadensis is only known to occur in Berrien County, Michigan, where it is frequent in old dune slopes. It also occurs in swampy woodlands. Outside the region it grows in cool, moist valleys or ravines, and is fond of rocky ridges and slopes. However, T. canadensis will grow in a variety of sites and soils. Seedlings are often found growing on rotting logs and moss covered rocks. T. canadensis is a shade-tolerant tree that can live 600 years or more. It grows slowly, existing for 50 - 100 years in the shaded understory until finally reaching the overstory. Over time, the litter from its fallen twigs and needles causes acidic soil conditions. This, combined with the tree's shade and absorption of moisture, discourages most plants from growing beneath it.
Occurence in the Chicago region: native
Notes: Numerous cultivars have been developed from T. canadensis, including shrubs, dwarfs, and graceful trees. The wood is not very durable, but is used for pulp, general construction, boxes, crates, sashes, doors, and cabinets. It is not recommended for firewood because of its tendency to pop, shooting sparks for several feet. The bark was once the main source of natural tannin for leather.
Etymology: Tsuga is the Japanese word for the hemlock tree. Canadensis refers to Canada, but is also used in reference to North America (a result of early French influence).
Author: The Morton Arboretum
From Flora of Indiana (1940) by Charles C. Deam
Local in the state and usually restricted to a fringe of trees on the tops and slopes of high sandstone bluffs along streams. Rapidly disappearing in some of its stations.
Indiana Coefficient of Conservatism: C = 10
Wetland Indicator Status: FACU
Deam (1932): Hemlock is of no economic importance in Indiana. The bark is much used in tanning. Hemlock is frequently used for a hedge plant.
Tree to 30 m, the leader nodding; twigs pubescent; lvs 8-15 mm, blunt, usually minutely spinulose on the margin, twisted at the petiolar base to form flat sprays; cones thickly ellipsoid, 12-20 mm, scales persistently erect or ascending, the exposed portion of the middle ones distinctly broader than long. Moist soil, esp. on rocky ridges and hillsides; N.S. to Mich., Wis., and occasionally Minn., s. to N.J., Del., O., and Ind., and in the mts. to Ga. and Ala.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.
©The New York Botanical Garden. All rights reserved. Used by permission.
Citation: The vPlants Project. vPlants: A Virtual Herbarium of the Chicago Region. http://www.vplants.org
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