Flower:

Flowers are borne on ½ to 1 inch long stalks, in clusters (fascicles) at the leaf axils along the stem. Flowers are ¼ to ½ inch across, white to pale pink with deeper pink streaks, with five squarish petals, the flat tips with slight, wavy lobes. In the center is a column of pink styles and numerous white stamens. The 5 sepals are broadly triangular and pointed, about half the length of the petals and hidden behind the flower.

Leaves and stems:

Leaves are round to kidney shaped, mostly deeply heart-shaped at the base, 1 to 3 inches wide, on stalks 3 to 6 inches long. The blade has 5 to 9 shallow, round to pointed lobes with sharp or blunt teeth around the edges. Upper surface is dark green and smooth to sparsely hairy, the lower surface lighter green and more densely hairy. The stems and leaf stalks have very fine, short hairs becoming nearly smooth with age. Stems are 4 to 12 inches long and branch out from the base. Often there is one or several central erect stems with other stems spreading prostrate on the ground, ascending at the tips (decumbent).

Fruit:

Fruit is flat and round, much like a wheel of cheese though its center is dimpled. The wheel is about ¼ inch across, sitting in a leafy cup formed by the now visible sepals. It is divided into 13-15 seed containing carpels that split apart at maturity.

Individual carpels are crescent moon shaped, the outer surface smooth with a finely hairy coat, the flat sides are smooth as well.

Notes:

Common Mallow and its similar cousin Round-leaved Mallow (Malva rotundifolia) are old world introductions now widely distributed across North America. They exhibit the same weedy behavior, appearing in lawns, gardens, agricultural fields, urban waste areas, even cracks in concrete. Though the leaves are much the same the species are not really difficult to tell apart if flowers or fruit are present. While still small, Malva neglecta flowers are more visibly showy, twice the size of M. rotundifolia, completely hiding the shorter sepals, and often brightly shaded pink with deeper colored streaks. More reliable yet is the smooth, finely hairy surface of its fruit. In comparison, the sepals of M. rotundifolia are about as long as the petals, which are more consistently white, and its fruit has a noticeably bumpy texture. We have little doubt that both species are under-reported in Minnesota.