Cathayeia Ohwi; Polycarpa Linden ex Carrière (1868), not Linnaeus (1759), nor Polycarpaea Lamarck (1792).

Trees, deciduous, dioecious. Leaves alternate; stipules small, caducous; petiole elongate, with two sessile discoid or shortly cylindric glands at apex, sometimes with additional glands along petiole length; leaf blade palmately 3-5-veined from base, glandular-toothed. Flowers hypogynous, unisexual, many, in terminal and axillary pendulous panicles, these sometimes racemelike; bracts caducous; pedicels articulate. Sepals (3-)5(or 6), imbricate, free or joined only at base, caducous. Petals absent. Disk glands present. Staminate flowers: stamens many, inserted on disk, ca. as long as sepals; filaments free, slender, softly hairy; anthers elliptic, longitudinally dehiscent, basifixed; disk lobes many, small, set among stamen bases; reduced ovary present. Pistillate flowers: staminodes many, surrounding ovary base, resembling stamens but smaller and sterile; disk lobes many, small, set among staminode bases; ovary superior, 1-loculed, with (3-)5(or 6) placentas; ovules many; styles (3-)5(or 6), ± erect, cylindric, connate at base, apex dilated to form a nearly peltate, flattened, subcircular (actually U-shaped) stigma. Fruit a berry; pericarp thin. Seeds many.

"Idesia fargesii" and "I. polycarpa var. fargesii" are not treated here because no protologues could be traced and neither name is included in the International Plant Names Index (www.ipni.org). The taxon is represented at K by four sheets: Farges 76 (two sheets), Sichuan, annotated "Idesia polycarpa var. fargesii Franch."; Farges s.n., same locality, annotated "Idesia fargesii Oliver"; and Cavalerie 2981, Guizhou, annotated "Idesia fargesii Franch." All are duplicates from P. No significant differences were found between this material and I. polycarpa. Among the Farges specimens, all leaves are glued abaxial surface down; abaxial leaf surfaces of the Cavalerie sheet are more or less glabrous.

One species: China, Japan, Korea.