About 1000 species native to the tropical regions belong to the Begoniaceae family. Their name comes from the surname of Michel Begon, governor of the Antilles, who first described them around 1700. These plants usually have a tuber with several fleshy buds. They can be divided into three groups: annual begonias, perennial tuberose begonias, and perennial begonias with ornamental leaves.

Annual begonias: derive from B. semperflorens, native to Brazil. This species is grown from seeds that are very small and delicate; one gram contains about 75,000 seeds. Annual begonias have a long flowering period—from May to October—and can produce simple flowers as well as double flowers. They may also be ornamental depending on the colour of their leaves which varies from green to red. Annual begonias grow well in full sun and prefer soils rich in organic matter.

Tuberous Begonias: the flowers of this species are generally very showy and derive from the transformation of the stamens. This is why male plants have prettier flowers, even though they last less. Tuberous begonias like hot, shady locations. The soil must be cool and moist, though well-drained because the tuber is very sensitive to root rot.

Begonias with ornamental leaves: usually rhizomatous and can be propagated by dividing the rhizome or by using stem cuttings. Begonia rex is the progenitor of this group which comes from India. These begonias can also be propagated from leaf cuttings. In this case, one cuts a part of the leaf, presses it against a moist compost, and within 30 days one obtains new plants. These plants, suitable for shade or part-shade, can be grown in moist soils with a lot of humus. They do not tolerate cold climates. The worst enemies of begonias are red spider mites and nematodes, which attack the leaves; and root rot, which attacks the bulb or rhizome. Careful consideration must be given to where they are planted: annual plants need full sun; tuberous and ornamental-leaved ones require part-shade and frequent watering without waterlogging.

pianta da begonia