- Name also: Common Mallow, Dwarf Malva, Roundleaf Mallow, Buttonweed, Cheesweed, Cheeseplant
- Family: Mallow Family – Malvaceae
- Growing form: Annual herb.
- Height: 15–50 cm (6–20 in.). Stem limp, abundantly branched, hairy–glabrous.
- Flower: Regular (actinomorphic), 1.5–2.5 cm (0.6–1 in.) wide. Petals 5, white, sometimes pinkish, red-veined, with notched tip. Calyx 5-lobed, outer calyx 3-leaved, leaves narrowly linear. Stamens many, filaments fused into a tube surrounding gynoecium. Pistil of several fused carpels. Flowers auxillary in groups of 2–5(–10).
- Leaves: Alternate, long-stalked, stipulate. Blade kidney-shaped, 4–7 cm (1.56–2.6 in.), shallowly 5–7-lobed, lobes widely triangular, with toothed margins.
- Fruit: Wide, flat, ring-like, 12–15-sectioned schizocarp. Mericarps with smooth surface, sparsely hairy, 1-seeded.
- Habitat: Yards, walls, flower beds, lanes, wasteland, harbours.
- Flowering time: July–September.
Most garden mallows are large and handsome plants with large flowers. In Finland there is only one original mallow species that grows in the wilds. The species is quite rare low mallow (Malva pusilla). Even more rare in Finnish nature is dwarf mallow which looks quite much the same: both species are quite small-flowered compared to garden mallows and both have roundish leaves and schizocarp looking like small cheese (that’s why the unofficial names cheeseweed and cheesplant). Dwarf mallow grows as a casual alien, especially in harbour towns in the same kinds of places as low mallow. The species can be differentiated by e.g. their flowers: dwarf mallow’s petals are approximately two times the size of low mallow’s.
Low Mallow (Round-leaved Mallow)
The clearest difference between low mallow and dwarf mallow when flowering is the size of the petals compared to the sepals: dwarf mallows petals are 2 times longer than its sepals, low mallow’s just a bit longer. Evident during the fruiting stage: dwarf mallow’s carpels have blunt corners and almost glossy surfaces while low mallow’s are sharp-cornered with a wrinkled surface. There is reason to doubt if low mallow’s modest-sized petals are enough to attract the pollinator’s attention through a mass of leaves: probably this plant, which follows human activity, is to a large extent self-pollinating. Low mallow’s nectar is located on the upper surface of the sepals – an insect looking for it has to push its proboscis between the petals to reach it, and in the course of doing so touches the anthers and stigmas, thus pollinating the flower. Low mallow is classified as vulnerable.