Malus

Malus ( or /‘mael@s/) 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. Other species include crabapples and crabapples. crabtrees is another common name. wild apple is another common name. rainberries are another commonly used term.

The temperate zone of North Hemisphere is where the genus can be found.

Description

Apple trees are typically 4-12 m (13-39 ft) talI at maturity, with a dense, twiggy crown. The leaves are alternate, simple, and 3-10 cm (1.2-3.9 in) long. They have a serrated margin. The flowers are borne in corymbs and have five petals. They can be either white, pink, or red. Flowering takes place in the spring after 50 to 80 growing degree days. This varies depending on 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, and therefore self-pollination is impossible, making pollinating insects essential.

Many cultivars are self-pollinating such as Granny Smith or Golden Delicious. There are considerably fewer of these, 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.

Cultivation

Crabapples are popular as compact ornamental trees, providing blossom in Spring and colourful fruit in Autumn. They can often be found throughout the winter. Many hybrid cultivars were selected.

To enhance the beneficial characteristics of domestic apples, some crabapples can be used as rootstocks. For example, the rootstocks of Malus baccata varieties are used to give additional cold hardiness to the combined plants for orchards in cold northern areas.

They are also used as pollinizers in apple orchards. Crabapple varieties are chosen to bloom in the same season as the apple variety. The crabs are then planted on the sixth or seventh trees. Or, the limbs of a crab tree can be grafted onto the apple trees. In emergencies, a bucket or drum bouquet of crabapple flowering branches are placed near the beehives as orchard pollenizers. Also see Fruit tree pollination.

Because of the plentiful blossoms and small fruit, crabapples are popular for use in bonsai culture.

Cultivars

The following have won the Royal Horticultural Society’s Award of Garden Merit:-

Other varieties are dealt with under their species names.