Manchurian crab apple

Description

Malus mandshurica, the Manchurian crab apple, is a species of Malus found in China, far eastern Russia, North Korea, and Japan. Some authorities consider it to be a variety of the Siberian crab apple, Malus baccata. It is used as a rootstock for cultivated apples in China. Malus is a genus of about 30–55 species of small deciduous trees or shrubs in the family Rosaceae, including the domesticated orchard apple (M. domestica syn. M. pumila) – also known as the eating apple, cooking apple, or culinary apple. The other species are commonly known as crabapples, crab apples, crabtrees, wild apples, or rainberries. The genus is native to the temperate zone of the Northern Hemisphere. Apple trees are typically 4–12 m (13–39 ft) talI at maturity, with a dense, twiggy crown. The leaves are 3–10 cm (1.2–3.9 in) long, alternate, simple, with a serrated margin. The flowers 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). Many apples require cross-pollination between individuals by insects (typically bees, which freely visit the flowers for both nectar and pollen); these are called self-sterile, so self-pollination is impossible, making pollinating insects essential. A number of cultivars are self-pollinating, such as 'Granny Smith' and 'Golden Delicious', but are considerably fewer in number compared to their cross-pollination dependent counterparts. Several Malus species, including domestic apples, hybridize freely. They are used as food plants 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 1–4 cm (0.39–1.57 in) diameter in most of the wild species, to 6 cm (2.4 in) in M. sylvestris sieversii, 8 cm (3.1 in) 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.