Picrasma quassioides (picrasma; Chinese: 苦樹 ku shu, Japanese: ニガキ nigaki 'bitterwood'; also India quassia, quassia wood, shurni, quassia-wood, or quassiawood; syn. P. ailanthioides) is a species of Picrasma native to temperate regions of southern Asia, from the northeast of Pakistan east along the Himalaya and through southern, central and eastern China to Taiwan and Japan.It is a deciduous shrub or small tree growing to 10–15 m (rarely 20 m) tall with a trunk up to 50 cm diameter. The bark is smooth ...