(Bongard) Carrière, Traité Gén. Conif., ed. 2. 250. 1867.
Mountain hemlock, pruche de Patton
Bongard, Mém. Acad. Imp. Sci. St. Pétersbourg, Sér. 6., Sci. Math. 2: 163. 1832;
(A.Murray bis) Lemmon;
(A.Murray bis) Bertrand;
(A.Murray bis) McNab;
(A.Murray bis) Parlatore;
(A.Murray bis) Carrière;
(A.Murray bis) Lemmon; ´
(A.Murray bis) M.Van Campo-Duplan and Gaussen.
Trees to 40m; trunk to 1.5m diam.; crown conic. Bark charcoal gray to reddish brown, scaly and deeply fissured. Twigs yellow-brown, glabrous to densely pubescent. Buds oblong, 3--4mm. Leaves 10--25(--30)mm, mostly spreading in all directions from twigs, curved toward twig apex, thickened centrally along midline, somewhat rounded or 4-angled in cross section, both surfaces glaucous, with ±inconspicuous stomatal bands; margins entire. Seed cones oblong-cylindric, 3--6 ´ 1.5--3cm; scales broadly fan-shaped, 8--l5 ´ 8--15mm, apex rounded to pointed. 2 n =24.
Coastal and montane forests to alpine slopes (where it occurs in krummholz form); 0--2400m; B.C.; Alaska, Calif., Idaho, Mont., Nev., Oreg., Wash.
The wood of Tsuga mertensiana is somewhat inferior to that of western hemlock both for building purposes and as pulp. This is a very handsome tree with its branches densely clothed with pale, spreading leaves and is adaptable to a wide variety of climatic conditions.
M.Van Campo-Duplan and H.Gaussen (1948) postulated that this taxon originated by hybridization between Picea and Tsuga . Although this is unlikely, some characteristics such as leaf arrangement and shape, phenolic chemistry, and pollen grain structure lend some support for this hypothesis.