Apple — The apple is the pomaceous fruit of the apple tree, species Malus domestica in the rose family Rosaceae. It is one of the most widely cultivated tree fruits. The tree is small and deciduous, reaching 5–12 m tall, with a broad, often densely twiggy crown. The leaves are alternately arranged simple ovals 5–12 cm long and 3–6 cm broad on a 2–5 cm petiole with an acute tip, serrated margin and a slightly downy underside. Flowers are produced in spring simultaneous with the budding of the leaves. The flowers are white with a pink tinge that gradually fades, five petaled, 2.5-3.5 cm in diameter. The fruit matures in autumn, and is typically 5–9 cm diameter. The centre of the fruit contains five carpels arranged in a five-point star, each carpel containing one to three seeds.
The tree originated from Asia, where its wild ancestor is still found today. There are more than 7,500 known cultivars of apples resulting in range of desired characteristics. It should be noted however, that cultivars vary in their yield and the ultimate size of the tree, even when grown on the same rootstock.
The apple tree was perhaps the earliest tree to be cultivated, and their fruits were improved through selection over a period of thousands of years by early farmers. Alexander the Great is credited with finding dwarfed apples in Asia Minor in 300 BC; those he brought back to Greece might have been the progenitors of dwarfing rootstocks. Apples were brought to North America with colonists in the 1600s, and the first apple orchard on this continent was said to be near Boston in 1625. Winter apples, picked in late autumn and stored just above freezing, have been an important food in Asia and Europe for millennia, as well as in Argentina and in the United States since the arrival of Europeans. In the 1900s, irrigation projects in Washington state began and allowed the development of the multi-billion dollar fruit industry, of which the apple is the leading species.
Like most perennial fruits, apples ordinarily propagate asexually by grafting. Seedling apples are different from their parents, sometimes radically. Most new apple cultivars originate as seedlings, which either arise by chance or are bred by deliberately crossing cultivars with promising characteristics. The words ‘seedling’, ‘pippin’, and ‘kernel’ in the name of an apple cultivar suggest that it originated as a seedling. Apples can also form bud sports (mutations on a single branch). Some bud sports turn out to be improved strains of the parent cultivar. Some differ sufficiently from the parent tree to be considered new cultivars.