japonica var. japonica
a 0.5-1.5m tall perennial seen everywhere in fields and mountains.
Stems are thick and hollow and lengthen rhizomes sideways long to
make new growths at the ends. Young stems are edible raw. Leaves are
alternate, each 6-15cm long, in the oval shape, the lots becoming
pointed abruptly. Branches emerge from the leaf axils, and set many
small flowers at the ends. P.cuspidatum is
dioecious. Corollas, varying from white to red, are cleft in five
lobes. Bloom time: July- October.