Venice Mallow

Hibiscus trionum

Weed Description
A summer annual with divided leaves and showy yellow and purple flowers. Venice mallow is primarily a weed of agronomic and nursery crops that is found throughout the eastern half of the United States.

Seedlings
Cotyledons are round and occur on long hairy petioles. First true leaves are alternate and irregularly shaped with a toothed margins. All subsequent leaves are lobed at least 3 times.

Leaves
Alternately arranged along the stem and are approximately 3 inches wide and long. Leaves are divided into at least 3 distinct lobes, but may be divided into as many as 7 lobes. All lobes have margins that are toothed. All leaves occur on long petioles and are without hairs (glabrous) on the upper surface and have hairs on the lower surface.

Stems
Erect, hairy, and branching from the base.

Flowers
Arise from the position between the stem and leaf petioles (leaf axils). Flowers consist of 5 petals that are pale yellow to white in color with a purple base. The 5 sepals resemble a membranous bladder with distinctive dark green veins.

Fruit
A round, hairy capsule that is surrounded by the sepals.

Roots
A shallow taproot and a fibrous root system.

Identifying Characteristics
The lobed leaves, membranous sepals that resemble a bladder, and yellow and purple flowers are all characteristics that help in the identification of Venice mallow.

Office of Programs

University of Missouri

Venice Mallow

Hibiscus trionum