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Conservation status

Pseudotsuga japonica

(Shirasawa) Beissner 1896

Common names

Toga-sawara [Jap.] (Iwatsuki et al. 1995); Japanese Douglas Fir (Dallimore et al. 1967).

Taxonomic notes

Syn: Tsuga japonica Shirasawa 1895 (Farjon 1998).

Description

Monoecious. Trees to 30 m tall and 150 cm dbh, the trunk clear of branches for about two-thirds the height of the tree. Bark dark brown, longitudinally fissured, more or less separating into plates, becoming greyish on very old trees. Shoots pale yellowish brown, glabrous, with longitudinal grooves; second year's branches grayish, with numerous more or less elevated pulvini. Winter buds very conspicuous, spindle-shaped as in other species, with shining brown, non-resinous scales. Leaves spirally arranged, linear, straight or slightly curved, 15-25 mm long, 1.5 mm wide, apex notched, upper surface grooved from base to apex, shining green on upper surface, two stomatal bands on lower surface, 2 resin canals near sides. Flowers in April. Pollen cones axillary on previous year's shoots, cylindric, brownish yellow, with numerous stamens. Seed cones the smallest of the genus, terminal on short branchlets, ovoid or oblong-ovoid, 4-5 cm long, 2-2.5 cm across, brown with glaucous patches when young, chocolate-brown at maturity; with 15-20 thick woody ovuliferous scales, margin minutely toothed or entire, each scale covered by a bract scale ca. 20 mm long and 4-5 mm wide with the three-lobed terminal portion strongly reflexed over the scale below, the central awn-like lobe narrower and longer than the short, blunt, lateral lobes. Cones ripen in October. Seeds shining dark brown above, pale mottled brown beneath, triangular-obovate, 6-9 mm long, 5 mm wide; wings dark brown, broad, 10-13 mm long, 6 mm wide. It is most easily distinguished from other species in the genus by its hairless shoots and small cones" (Dallimore et al. 1967, Iwatsuki et al. 1995).

Distribution and Ecology

Japan: Honshu (Kii Peninsula) and Shikoku (Kochi Prefecture). In temperate forests at 500-1100 m elevation (Iwatsuki et al. 1995).

Big tree

Oldest

Dendrochronology

Ethnobotany

Observations

Remarks

Citations

Beissner. 1896. Mitt. Deutsch. Dendr. Ges. 5: 62.

Shirasawa. 1895. Bot. Mag. Tokyo 9: 86, t. 3.

See also

Farjon (1990).

Last Modified 2012-11-23