1. Cunninghamia R. Brown ex Richard & A. Richard in A. Richard, Comm. Bot. Conif. Cycad. 80, 149. 1826.
杉木属 shan mu shu
Trees evergreen, monoecious; branches whorled or irregularly so; winter buds ovoid. Leaves spirally arranged, sessile, lanceolate or linear-lanceolate, stomatal bands present on both surfaces but fewer adaxially, base attenuate, margin serrulate. Pollen cones terminal, clustered; microsporophylls many, spirally arranged, sessile, scalelike, distal margin serrulate; pollen sacs 3, pendulous. Seed cones 1-3 together, terminal, globose, ovoid, or cylindric-ovoid; bracts and cone scales spirally arranged, sessile, connate proximally; bracts persistent, broadly ovate or triangular-ovate, flat, large, leathery, base cordate, margin irregularly and finely serrulate, apex long acuminate, hard; ovules 3 per bract axil, sessile; cone scales of mature cones sessile on and fused to proximal middle part of abaxial side of bract, minute, distal part free, 3-lobed, lobes irregularly serrulate at apex. Seeds 3, sessile on adaxial side of cone scale, flat, with 2 narrow, lateral wings. Cotyledons 2. Germination epigeal. 2n = 22*.
One species: ?Cambodia, China, Laos, N Vietnam.
The minute cone scales of Cunninghamia have often been overlooked, and in much of the literature what is termed the cone scale is in fact the bract.