an annual herb height of 0.3-1m, grows in colonies in damp spaces,
such as water's edges, paths between rice fields, etc. The stems
have downward prickles, and lower parts creep on the ground. Leaves
are alternate, ovate to hastate, 4-10cm in length, tips pointed,
bases spreading out like ear shape. Flowers, ranging from red-purple
to white, bloom in mass on branch tops. Bloom time: July-October.