// SPECIES PROFILE · PERENNIAL · NATIVE

Longroot smartweed

Polygonum amphibium var. emersum

Longroot smartweed (Polygonum amphibium var. emersum) is a perennial in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 2a–11a. Blooms Jun–Sep.

// QUICK FACTS

Family: —
Group: perennial
Native range: Native to 46 U.S. states, including AR, AZ, CA, CO, CT, DC…
USDA hardiness: Zones 2a–11a
Mature size: —
Sun: —
Water: —
Bloom: Jun–Sep
Wildlife value: Pollinator and wildlife support
Ecological role: native species profile

Longroot smartweed (Polygonum amphibium var. emersum) — *Polygonum amphibium var. emersum* — Longroot smartweed. Photo via iNaturalist — (c) Ryan Sorrells, some rights reserved (CC BY).

Field Notes

[ growing · ecology · siting · care ]

Longroot smartweed (Polygonum amphibium var. emersum) is a perennial in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 2a–11a. Blooms Jun–Sep.

Why it's on this list: native species profile. Native-range data from the Lady Bird Johnson Wildflower Center (NPIN), cross-checked against iNaturalist observations. Part of Rooted Revival's regional native plant catalog — true natives for Oklahoma, Arkansas, Missouri and Kansas.

Companion Planting

[ guild · polyculture · cross-layer pairings ]

In the same native range, longroot smartweed pairs naturally with: Broadleaf Arrowhead (Sagittaria latifolia), Lady Fern (Athyrium filix-femina), Wild Strawberry (Fragaria virginiana), Yarrow (Achillea millefolium).