Uncaria rhynchophylla (Miq.) Miq. Rubiaceae
This vine is found in the south of Boso peninsula Japanese mountain forest. Its flowering period is June to July. Thorns in the axils of leaves cling to other vegetation. The name of the genus is derived from the Latin word uncus, meaning hook.
Part used: hook or the hook-bearing stem
Medicinal use: sedative
Main component: rhynchophylline
Small terminal or axillary yellowish-green flowers appear to form capitulum inflorescences.
The name of the herbal medicine is "Uncaria Hook".