6. Sequoiadendron J. Buchholz, Amer. J. Bot. 26: 536. 1939.
巨杉属 ju shan shu
Wellingtonia Lindley (1853), not C. F. W. Meissner (1840).
Trees evergreen, tall and massive, very long lived, monoecious; winter buds small, with bud scales. Leaves spirally arranged, sessile, appressed to branchlets or ± radially spreading, all scalelike, ovate to lanceolate, flat adaxially, convex abaxially, stomatal lines present on both surfaces, resin canal central. Pollen cones solitary at apex of short branchlets, sessile. Seed cones terminal, pendulous, pedunculate, elliptic, ripening in autumn of 2nd year, persistent on tree for many years; ovules 3-12 per bract axil, erect; cone scales shield-shaped, woody when mature, apically grooved. Seeds 3-9 per cone scale, in 1 or 2 rows, flattened, with 2 lateral wings broader than body of seed. Cotyledons (3 or)4(or 5). 2n = 22.
One species: United States; introduced in China.
