// SPECIES PROFILE · ANNUAL · NATIVE

Curlytop knotweed

Polygonum lapathifolium

Curlytop knotweed (Polygonum lapathifolium) is a annual in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 1a–11b. Mature size 6"–3'. Blooms Jul–Oct.

// QUICK FACTS

Family: —
Group: annual
Native range: Native to 50 U.S. states, including AK, AL, AR, AZ, CA, CO…
USDA hardiness: Zones 1a–11b
Mature size: 6"–3'
Sun: —
Water: —
Bloom: Jul–Oct
Wildlife value: Pollinator and wildlife support
Ecological role: native species profile

Curlytop knotweed (Polygonum lapathifolium) — *Polygonum lapathifolium* — Curlytop knotweed. Photo by Hardyplants at English Wikipedia via Wikimedia Commons (Public domain).

Field Notes

[ growing · ecology · siting · care ]

Curlytop knotweed (Polygonum lapathifolium) is a annual in the — family. Native range includes AR, KS, MO, OK. Hardy in zones 1a–11b. Mature size 6"–3'. Blooms Jul–Oct.

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, curlytop knotweed pairs naturally with: Common Sunflower (Helianthus annuus), Pitseed goosefoot (Chenopodium berlandieri), Pitseed goosefoot (Chenopodium berlandieri var. boscianum), Bush's goosefoot (Chenopodium berlandieri var. bushianum).