Venice Mallow
Hibiscus trionum

Family: Mallow (Malvaceae)
AKA: Flower-of-an-hour, Bladder Ketmia, Rosemallow
Photo taken on: September 20, 2017
Location: Abiquiu, NM
Life Zones: Plains to foothills
Habitat: Fields, disturbed soil, gardens, roadsides

Grows to 18" high, erect or sprawling, with hairy stems and leaves deeply divided into three or five lobed leaflets. Flowers are up to 2" across and have five white to pale yellow petals with purple bases and bright orange stamens. The sepals under the flower are translucent, ridged and hairy and give way to bladder-like seed pods. The flowers bloom only when it is sunny and stay open for a few hours before wilting. It was introduced from Europe as an ornamental but is now considered a weed in many parts of the country.

It is a listed noxious weed in Colorado.

Flora of North America reference.