Malus by the larvae of a large number of Lepidoptera species; see list of Lepidoptera that feed on "Malus". The fruit is a globose pome, varying in size from diameter in most of the wild species, to in "M. sylvestris sieversii", in "M. domestica", and even larger in certain cultivated orchard apples. The centre of the fruit contains five carpels arranged star-like, each containing one or two seeds. For the "Malus pumila" cultivars, the culinary, and eating apples, see Apple. Crabapples are popular as compact ornamental trees, providing blossom in Spring and colourful fruit in Autumn. The fruits often persist throughout
Malus are borne in corymbs, and have five petals, which may be white, pink or red, and are perfect, with usually red stamens that produce copious pollen, and a half-inferior ovary; flowering occurs in the spring after 50–80 growing degree days (varying greatly according to subspecies and cultivar). Apples require cross-pollination between individuals by insects (typically bees, which freely visit the flowers for both nectar and pollen); all are self-sterile, and (with the exception of a few specially developed cultivars) self-pollination is impossible, making pollinating insects essential. Several "Malus" species, including domestic apples, hybridize freely. They are used as food plants