Ohio Perennial and Biennial Weed Guide

Family:

Mallow Family (Malvaceae)

Other Names:

button weed, cheese mallow, cheese weed, cheeses, dwarf mallow, garden mallow, low mallow, malice, round dock, round-leaved mallow, running mallow.

Origin and Distribution:

A Eurasian species, common mallow can now be found growing throughout North America. In Ohio, it occurs in nearly every county. This weed commonly occurs in disturbed sites such as roadsides, railroads, waste places, gravel pits, nurseries, gardens, and cultivated fields. It is frequently found growing in yards around homes, buildings, and barns.

Plant Description:

Common mallow is a summer or winter annual that has been known to sprout a second year from a biennial root crown. Distinguishing characteristics are the fruits, which resemble tiny wheels of cheese, and kidney-shaped leaves that are shallowly lobed, appear slightly crinkled, have toothed edges, and attach to stems by way of long stalks (petioles). Reproduction is by seeds, but fragmented stems can root at the nodes if conditions remain sufficiently moist for a long enough period of time.

• Root System:

  Common mallow has a straight taproot that can be various lengths. Plants also have a coarsely branched secondary root system.

• Seedlings and Shoots:

  Young plants grow as basal rosettes. The first two leaves are smooth and heart shaped. Then, leaves are produced that are similar to those of adult plants. They are alternate (1 leaf per node), hairy, and appear crinkled with the tissue between veins puckered. Before they fully open, leaves are folded in bud to form an inverted cone. Petioles are long and hairy.

• Stems:

  Stems are 4 to 34 inches long, branched, covered with short hairs, and usually trail along the ground until they turn upright at the end.

• Leaves:

  Leaves are about 1 1/2 inches wide, alternate (1 leaf per node), kidney-shaped, toothed around the edge, and have between 5 to 9 shallow lobes. They have prominent veins that radiate from the center of the leaf. Also, leaves are covered on both sides by short hairs. Leaves attach to stems by way of long petioles.

• Flowers:

  Flowers are about 1/2 inch wide and have 5 petals that are notched at their tip and range from white to rose to lavender. Flowers arise either alone or in clusters from stem axils. Common mallow flowers resemble tiny hollyhock flowers.

• Fruits and Seeds:

  Fruits look like disks consisting of 10 to 20 rounded, flattened sections aggregated in such a manner that they form a ring. As fruits ripen and become dry, segments tend to separate. Each segment contains one seed. Seeds are nearly round and range from reddish brown to black.

Similar Species:

Ground ivy (Glechoma helderacea) is easily distinguished from common mallow by its leaves that are opposite (2 leaves per node) and have edges with rounded teeth. Also, the stems of ground ivy are square in cross section and smell minty. It is more difficult to distinguish round-leaved mallow (Malva rotundifolia) from common mallow. The flowers of round-leaved mallow are about 1/4 inch wide, which is considerable smaller than those of common mallow. Also, round-leaved mallow fruits have an outer surface that is bumpy compared with common mallow fruits. In cross section, round-leaved mallow fruits are horse-shoe shaped while common mallow fruits are round. Round-leaved mallow and common mallow occur in similar habitats, but round-leaved mallow is not as wide spread.

Biology:

The primary months of growth for common mallow are April through November. Seeds germinate continuously during this time. Flowers appear from May until October. Common mallow can be controlled by hand-weeding, hoeing, and clean cultivation. Plants with fruits should be removed and burned.

Toxicity:

None known.

Facts and Folklore:

• Several common names for this weed include the word 'cheeses' in reference to the fruit, which is said to resemble a wheel of cheese.

• Fruits resemble a button, hence the common name 'button weed'.

• 'Malva' is said to refer to the emollient leaves.