Description from Flora of China
Trees evergreen, monoecious; branchlets arranged in a plane, spreading or ascending, flattened, prominently jointed. Leaves decussate, almost in whorls of 4, scalelike, base decurrent, dimorphic along branchlets: facial pairs flattened; lateral pairs boat-shaped, usually less than 4 mm, overlapping facial pairs, without conspicuous, white stomatal bands abaxially. Pollen cones terminal, solitary; microsporophylls 10-16, each with 2-5 pendulous pollen sacs. Seed cones terminal, solitary, oblong or ellipsoid-cylindric, dehiscent when mature in 1st year; cone scales 6, decussate, flat, only middle pair fertile, each fertile scale bearing 1 or 2 seeds; free bract apex a short mucro. Seeds with 2 subapical, unequal wings. Cotyledons 2.
Two species: China, Laos, Myanmar, Thailand, Vietnam, Mexico, United States; one species in China.