Coffea (coffee) is a genus of ten species of flowering plants in the family Rubiaceae. They are shrubs or small trees, native to subtropical Africa and southern Asia. Seeds of this plant are the source of the beverage coffee. The seeds are called "beans" in the trade. Coffee beans are widely cultivated in tropical countries in plantations for both local consumption and export to temperate countries. Coffee ranks as one of the world's major commodity crops and is the major export product of some countries.
When grown in the tropics coffee is a vigorous bush or small tree easily grown to a height of 3–3.5 m (10–12 feet). It is capable of withstanding severe pruning. It cannot be grown where there is a winter frost. Bushes grow best at high elevations. To produce a maximum yield of coffee berries (800-1400 kg per hectare), the plants need substantial amounts of water and fertilizer. Calcium carbonate and other lime minerals are sometimes used to reduce acidity in the soil, which can occur due to run off of minerals from the soil in mountainous areas. The caffeine content in coffee "beans" is a natural defense, the toxic substance repelling many creatures that would otherwise eat the seeds, as with nicotine in tobacco leaves.
There are several species of Coffee that may be grown for the beans, but Coffea arabica is considered to have the best quality. The other species (especially Coffea canephora (var. robusta)) are grown on land unsuitable for Coffea arabica. The tree produces red or purple fruits (drupes), which contain two seeds (the "coffee beans", although not true beans). In about 5-10% of any crop of coffee cherries, the cherry will contain only a single bean, rather than the two usually found. This is called a 'peaberry', which is smaller and rounder than a normal coffee bean. Some claim that peaberries have a different flavor profile in the cup, while others dispute this. Either way, it is often removed from the yield and either sold separately (such as in New Guinea Peaberry), or discarded.
The coffee tree will grow fruits after 3–5 years, for about 50–60 years (although up to 100 years is possible). The blossom of the coffee tree is similar to jasmine in color and smell. The fruit takes about nine months to ripen. Worldwide, an estimate of 15 billion coffee trees are growing on 100,000 km² of land.