Helwingia japonica, a
deciduous shrub inhabiting damp locations along mountain rivers in,
hills, or mountains, trunks are in bundles and branch well at upper
parts and grow to 1-3m in height with smooth green barks. Leaves are
alternate, blades measuring 3-16cm long, 1.5-6cm wide, broad-oblong,
with tips tail-like to pointed and bases obtuse or broadly cuneate.
Margins are with shallow serrations, the tips growing to awns toward
glands. Light green flowers set themselves on approximately central
positions of midribs; male flowers 4, and females generally 1,
occasionally 2-3. The flowers measure 4-5mm across, and the petals
are oval-triangular. Bloom time: April-May.