Persicaria hydropiper is
an annual herb of 30-60cm tall inhabiting water's edges. Leaves are
lanceolate- or long-oval-shaped, measuring 3-10cm. Ochreas are
cylindrical, with short hairs on the edges. Inflorescences are
4-10cm in size, the upper parts hanging down, with sparsely set,
slightly reddish-white flowers. Perianths are cleft into 4-5
segments. They taste hot. Bloom time: July-October.