Pterocarya sect. Cycloptera Franchet.

Trees deciduous, monoecious. Branchlets with chambered pith. Terminal buds oblong, naked. Leaves odd-pinnate; leaflets (5 or)7 or 9(or 11), margin serrate. Inflorescences lateral or terminal on old or new growth, pendulous; male and female inflorescences separate: male spikes in clusters of 3-5, lateral on old growth; female spike solitary, terminal on new growth. Flowers anemophilous. Male flowers with an entire bract; bracteoles 2; sepals 2; stamens 20-31, anthers pubescent. Female flowers subtended by a small, entire bract, adnate to bracteoles and virtually submerged in wing complex; bracteoles 2, united and adnate to ovary; sepals 4, adnate to ovary, free at apex; style short; stigmas commissural, 2-lobed, plumose. Fruiting spike elongate, pendulous. Fruit a disc-winged nutlet, 2-4-chambered at base. Germination most likely hypogeal.

* One species: China.

This taxon is sometimes treated as a section or subgenus of Pterocarya, but generic rank seems preferable, based on the fossil record and several distinctive features, including clusters of male spikes (vs. solitary), low pollen pore number (3-5 vs. 4-9), bract fused with bracteoles (vs. not fused), commissural stigmas (vs. carinal), and disc-winged nutlets (vs. 2-winged).