7. Sequoia Endlicher, Syn. Conif. 197. 1847.
北美红杉属 bei mei hong shan shu
Trees evergreen, very tall and massive, monoecious; winter buds small, with many overlapping bud scales. Leaves spirally arranged, sessile, dimorphic: those on main branchlets closely appressed or slightly spreading, ovate-oblong, scalelike; those on lateral branchlets 2-ranked, sessile, linear, adaxial surface with a few interrupted stomatal lines or none, abaxial surface with 2 white stomatal bands, base twisted, apex abruptly acute. Pollen cones solitary at apex of branch or in leaf axils, shortly pedunculate; microsporophylls numerous, spirally arranged, each with 2-5 pollen sacs. Seed cones terminal, pendulous, pedunculate, ovoid-ellipsoid or ovoid, ripening in 1st year, subtended by many spirally arranged, sessile, scalelike leaves; ovules 3-7 per bract axil, erect; cone scales of mature cones shield-shaped, woody. Seeds 2-5 per cone, flattened, with lateral wings. Cotyledons 2. 2n = 66.
One species: United States; introduced in China.