Scientific Name: Hibiscus trionum

Common Name: flower of an hour

Other Common Names: Venice mallow, bladder ketmia, modesty, shoo-fly, rose mallow

Synonyms: Trionum trionum

Leaves: 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. Roots: A shallow taproot and a fibrous root system

Identifying Characteristics: A summer annual with divided leaves and showy yellow and purple flowers.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.

Flower Seed Head: 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.

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

Where Found: Venice mallow is primarily a weed of agronomic and nursery crops that is found throughout the eastern half of the United States.

  • Life cycle: summer annual

  • Milky sap: Not Present

  • Plant type: Herb

  • Thorns: Not Present

  • Plant family: Malvaceae

  • Leaf arrangement: alternate

  • Leaf shape: spatulate; round; triangle

  • Ochrea: Not Present

  • Leaf margin: serrated; lobed

  • Stem hairs: has hairs

  • Flower color: purple; white; yellow

  • Growth habit: upright and nonwoody; prostrate and nonwoody

  • Stem: round or oval

  • Leaf structure: palmate

  • Leaf hairs: has hairs

  • Flower symmetry: radial symmetery

  • Flower diameter: nickle; half dollar; quarter; dime

  • Root structure: taproot

  • Leaf stalk: shorter than leaf; longer than leaf