A small, much-branched perennial herb with tiny star-shaped hairs. Flowers in leaf axils of upper stems, about ⅜ inch across, with 5 yellow to orange-yellow petals; the stamens are united around the pistil (a feature of mallows). Blooms June–October. Leaves alternate, on long stems, ovate to oblong with crenate (scalloped) margins. Leaf stems have at their bases a small, spinelike projection, which is quite soft until the plant matures and dries out. Fruit a flattened ring that splits into 5 wedge-shaped sections (mericarps) each with a pair of short beaks toward the tip.
Similar species: Elliott’s sida (S. elliottii) grows on Crowley’s Ridge in southeast Missouri. It has 10 mericarps, flowers solitary (not clustered) in the leaf axils, and leaf stems shorter (not longer) than the accompanying flower stalk. Also, the weedy, introduced arrowleaf sida (S. rhombifolia) may soon be found in Missouri. It has only 1 beak per mericarp.
Stem length: to 2 feet.
Common nearly statewide.
Habitat and Conservation
Occurs on banks of streams and rivers, margins of pond and lakes, rarely savannas; also roadsides, railroads, edges of crop fields, pastures, and open, disturbed areas. Most likely introduced to our state. It’s a native of the New and Old World tropics.
A close look at the flowers, with the columnlike pistil with united stamens attached to it, shows this plant’s relationship to other mallows such as hibiscus, cotton, okra, and hollyhocks.
Biogeography is the study of how life forms are distributed spatially, across the land. The northern extent of this plant’s historic, native range is unclear. It was collected from our state as early as 1833, but those plants were growing in disturbed sites, so they were probably introduced.
Bees, butterflies, and skippers drink nectar from the flowers. The spiny projections on the seeds help them adhere to the fur of animals, which enables the new plants to disperse from the parent plant.