A survey conducted to determine the distribution of red horned poppy in western Oklahoma identified infestations in 14 Oklahoma and 3 Texas counties. Soil pH from infested fields ranged from 7.0 to 8.5. Red horned poppy grew as an annual, germinating in fall, spring, or summer. Plants that emerged in the fall survived −25 C, flowered in April and produced mature seed in June. Plants that emerged in April, flowered in June and produced mature seed in July. Corolla color varied from red to yellow with time of anthesis.
