Large-flowered evening primrose

Oenothera glazioviana is generally a biennial herb producing an erect stem approaching 1.5 metres in maximum height. It is roughly hairy in texture, the hairs with reddish blistering or glandular bases. The crinkly leaves are up to 15 centimeters long. The inflorescence is a showy spike of many large flowers. When in bud the long red sepals are visible. When in bloom each flower has four bright yellow petals up to 5 centimeters long which fade orange to red with age. The fruit is a lance-shaped capsule 2 or 3 centimeters long.