Polygonum orientale, an
introduced annual, now grows in the wild in uncultivated lands; the
stems grow up to 1-1.5m in height, with alternate, 10-20cm-long,
tip-pointed oval to broad oval leaves, the bases are in the
circular- to heart-shape, the tips pointed. Inflorescences are long,
5-10cm long, stout, and hang down. Perianths are cleft into five
lobes. Bloom time: July-October.