Common mallow

Common mallow, also called cheeseweed or buttonweed, is a low, spreading plant with stems that grow prostrate to somewhat upright from a thick, straight taproot. The leaves are alternate, rounded to kidney-shaped with shallowly toothed, scalloped margins and palmate veins, and are borne on long petioles, giving the plant a distinctive rounded-leaf look. Flowers are small with five notched petals, white to pale lavender often marked with darker violet veins. The fruit is the most diagnostic feature: a flattened, segmented, button-like disk that resembles a tiny wheel of cheese, which gives the plant its common names.

Common mallow spreads low, rounded-leaf rosettes and trailing stems that shade and crowd out turfgrass, creating coarse patches that disrupt lawn uniformity and leave open gaps when the deep-taprooted plants are removed. Its tolerance of stress means it stays green and competitive while desirable grass struggles on dry, compacted sites, and the persistent seed bank and tough taproot make established infestations difficult to clear and prone to recurrence.

Common mallow behaves as an annual or biennial and reproduces by seed. Plants germinate from seed, develop a stout taproot, and flower from late spring through fall (roughly May to October), producing the characteristic cheese-wheel fruits and abundant hard-coated seed that can persist in the soil. The deep, tough taproot makes established plants difficult to remove mechanically and allows the plant to survive adverse conditions while it completes its life cycle.

Common mallow is a tough survivor that tolerates cold, drought, and dry, compacted soils, and it is most common in low-maintenance turf, landscapes, and neglected or disturbed ground. It exploits thin, weak stands and bare or compacted areas where competition is low, establishing readily in full sun. Poorly maintained, infrequently irrigated, or heavily trafficked sites are particularly prone to invasion, and once a plant develops its taproot it persists and seeds the surrounding area.