About

Tovara virginiana var. filiformis is a perennial in the Polygonaceae notable for seedpods that can 'jump' when disturbed. It is unusually shade-tolerant for a genus that mainly prefers sun and flowers from midsummer into early autumn. Inflorescences are slender stalks of small white to greenish-white flowers. Leaves are larger and more oval than in most related species and can show a chevron-shaped marking on some leaves.

Wikipedia contributors, CC BY-SA 4.0 — Persicaria virginiana

About the genus

Persicaria is a genus of herbaceous flowering plants in the knotweed family, Polygonaceae. Plants of the genus are known commonly as knotweeds or smartweeds.

In the garden

Tovara virginiana var. filiformis is a North American perennial in the buckwheat family that stands out because ripe seedpods can eject seeds several feet when touched. The plant bears slender flowering stalks of small white to greenish-white blooms from midsummer into early autumn; fruiting flowers develop two downward-pointing, hook-tipped styles. Leaves are alternate and possess the characteristic stipular sheath (ocrea) with a bristle-fringed edge that often browns with age, and individual leaves may display a chevron-shaped marking. Give it a shady or part-shady position where it will receive less direct sun than typical members of the genus. Expect visible variation between cultivated selections and wild plants: leaf markings and the degree of pink tinging on flowers can differ between plants. Remove spent stalks if you want to limit self-seeding, and be aware that naturalised or escaped plants can show greater variation than nursery stock. In the UK it suits woodland-style beds, shaded borders and beneath trees where its slender flower spikes add vertical movement in summer and autumn. Check plant labels for named selections if you require a consistently marked foliage form, and deadhead flower stems before seedpods ripen if you need to prevent seedlings from appearing metres from the parent.