Description from Flora of China
Shrubs or small trees evergreen. Branches usually 3-ridged or -angled. Leaves alternate, ± sessile, elliptic-lanceolate or elliptic-obovate, usually ± leathery, pinnately veined, lateral veins inconspicuous. Inflorescences axillary; male ones cymose; bisexual and female ones often 1-flowered; bracts and bracteoles on male inflorescences caducous. Flowers unisexual (when plants dioecious) or bisexual. Bisexual flowers: perianth tube mostly connate to ovary, lobes 3(or 4), triangular or ovate, with a tuft of hair adaxially. Stamens 3(or 4), short, on the base of lobes; anthers ovoid, cells distinct, parallel, dehiscence longitudinal. Disk nearly flat, sinuate at margin. Ovary inferior, 1-loculed; ovules 2-4. Style needle-shaped; stigmas 3(or 4)-parted. Male flowers: stamens slightly longer than bisexual flowers; ovary rudimentary. Female flowers: bracteoles more prominent; perianth tube shorter. Fruit a drupe, relatively small (to 1 cm), usually with rudimentary perianth at apex or with only rudimentary disk, exocarp fleshy, endocarp crustaceous. Seeds globose.
Osyris japonica Thunberg is Helwingia japonica (Thunberg) Dietrich (Helwingiaceae/Cornaceae s.l.).
Six or seven species: Africa, Asia, Europe; one species in China.