Persicaria is also known as Mountain Fleeces or Red Bistort, and it is part of the knotweed family. The plant is native to the Himalayas. It is an herbaceous perennial plant. The plant has tiny rose-red to white flowers that grow on pencil-thin spikes.  The spikes can grow 4 to 6 feet. The plant blooms throughout the summer until the first frost.  The plant is easy to grow in moist well-drained soil in full sun to partial shade. It will tolerate wet soil. The plant is deer tolerant and attracts birds and butterflies. While the plant is not invasive, it will perform best when it has room to spread. With its tall spikes, the plant does not do well in windy conditions. The plant also looks great in mixed containers. Divide the plant in spring or fall. Hardiness zones 4-7.