1. Cryptomeria japonica (Thunberg ex Linnaeus f.) D. Don, Trans. Linn. Soc. London, Bot. 18: 167. 1839.
日本柳杉 ri ben liu shan
Trees to 40 m tall; trunk to at least 2 m d.b.h.; bark reddish brown, fibrous, peeling off in strips; crown pyramidal; main branches whorled, horizontally spreading or slightly pendulous; branchlets usually pendulous, those of 1st year green. Leaves on leader branchlets borne at 15-45° to axis, those on short (fertile) branchlets at 30-55° to axis, subulate to linear, ± straight or strongly incurved, (0.4-)0.7-1.4(-2) cm × 0.8-1.2 mm (width measured near base of two wider surfaces), rigid, stomatal bands with 2-8 rows of stomata on each surface. Cones borne from 5th year onward. Pollen cones borne in racemes of 6-35, ovoid or ovoid-ellipsoid, (2-)2.5-5(-8) × (1.3-)2-3(-4) mm, each cone (except basal and apical) subtended by a leaf shorter than to 1.5 × length of cone. Seed cones borne in groups of 1-6, globose or subglobose, 0.9-1.6(-2.5) × 1-2(-2.5) cm; cone scales 20-30, proximal 2 margins often convex in outline, or all 4 margins ± concave in outline, middle part with or without distinct shoulders at widest point, apex usually recurved, umbo rhombic, distally with 4 or 5(-7) toothlike projections 1-3.5 mm. Seeds 2-5 per cone scale, brown or dark brown, irregularly ellipsoid or multiangular and ± compressed, 4-6.5 × 2-3.5 mm; wings 0.2-0.25 mm wide. Pollination Feb-Apr, seed maturity Oct. 2n = 22.
Forests on deep, well-drained soils subject to warm, moist conditions, also cultivated as an ornamental and planted for timber; below 1100 m to 2500 m. Native in Fujian, Jiangxi, Sichuan, Yunnan, Zhejiang; introduced in Anhui, Fujian, Gansu, Guangdong, Guangxi, Guizhou, Henan, Hubei, Hunan, Jiangsu, Jiangxi, Shandong, Sichuan, Taiwan, Yunnan, Zhejiang [Japan]
Fast-growing on deep, well-drained soils in montane areas with a warm, moist climate, but intolerant of poor soils and cold, drier climates. The wood is strongly rot resistant, easily
worked, and is used for buildings, bridges, ships, lamp posts, furniture, utensils, and paper manufacture. The species is also cultivated as an ornamental tree.
