Malus sieversii Malus sieversii Malus sieversii is a wild apple native to the mountains of Central Asia in southern Kazakhstan. It has recently been shown to be the primary ancestor of most cultivars of the domesticated apple ("Malus pumila"). It was first described (as Pyrus sieversii) in 1833 by Carl Friedrich von Ledebour, a German naturalist who saw them growing in the Altai Mountains. It is a deciduous tree growing to , very similar in appearance to the domestic apple. Its fruit is the largest of any species of "Malus" except "pumila", up to 7 cm diameter, equal in size to many
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