// SPECIES PROFILE · ANNUAL · NATIVE

Flatspine bur ragweed

Ambrosia acanthicarpa

Flatspine bur ragweed (Ambrosia acanthicarpa) is a annual in the — family. Native range includes KS, MO, OK. Hardy in zones 2a–11a. Mature size 6"–3'.

// QUICK FACTS

Family: —
Group: annual
Native range: Native to 19 U.S. states, including AZ, CA, CO, ID, KS, MN…
USDA hardiness: Zones 2a–11a
Mature size: 6"–3'
Sun: —
Water: —
Bloom: —
Wildlife value: Pollinator and wildlife support
Ecological role: native species profile

Flatspine bur ragweed (Ambrosia acanthicarpa) — *Ambrosia acanthicarpa* — Flatspine bur ragweed. Photo by Anthony Valois and the National Park Service via Wikimedia Commons (Public domain).

Field Notes

[ growing · ecology · siting · care ]

Flatspine bur ragweed (Ambrosia acanthicarpa) is a annual in the — family. Native range includes KS, MO, OK. Hardy in zones 2a–11a. Mature size 6"–3'.

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, flatspine bur ragweed pairs naturally with: Common Sunflower (Helianthus annuus), Rocky mountain bee-plant (Peritoma serrulata), Swamp verbena (Verbena hastata), Annual ragweed (Ambrosia artemisiifolia var. artemisiifolia).