It's About Coffee - Botany of Coffee

BOTANY

Botanical family of Coffee is Rubiaceae, which has some 500 genera and over 6,000 species. All species of Coffea are woody, but they range from small shrubs to large trees over 10 metres tall; the leaves can be yellowish, dark green, bronze or tinged with purple.

Family	Genus	Species (many including:)	Varieties (examples:)
Rubiaceae	Coffea	Arabica	Typica
		Canephora	Robusta
		Liberica

The two most important species of coffee economically are Coffea arabica (Arabica coffee) - which accounts for over 60 percent of world production - and Coffea canephora (Robusta coffee). Two other species which are grown on a much smaller scale are Coffea liberica (Liberica coffee) and Coffea dewevrei (Excelsa coffee).

Coffea arabica - Arabica coffee

The average Arabica plant is a large bush with dark-green oval leaves. It is genetically different from other coffee species, having four sets of chromosomes rather than two. The fruits are oval and mature in 7 to 9 months; they usually contain two flat seeds (the coffee beans) - when only one bean develops it is called a peaberry.

Coffea canephora - Robusta coffee

The term 'Robusta' is actually the name of a widely grown variety of this species. It is a robust shrub or small tree growing up to 10 metres in height, but with a shallow root system. The fruits are rounded and take up to 11 months to mature; the seeds are oval in shape and smaller than those of C. arabica. Robusta coffee has a caffeine content higher than Arabica

Basically, Arabica have a acid for brew characteristic and bitterness, full for Robusta