Begonia

The genus Begonia comprises about 1,500 species, of which about 150, plus nearly 10,000 varieties and hybrids, are marketed for garden use. They are native to the tropical and subtropical regions of America, Africa and Asia. The only other member of the family Begoniaceae is Hillebrandia, a genus with only one species in the Hawaiian Islands, and the genus Symbegonia which was recently included in Begonia.

The name for the genus, coined by Charles Plumier, a French botanist, honors Michel Bégon, a governor of the former French colony of Haiti, and was adopted by Linnaeus.

Description

They are herbaceous terrestrial plants (sometimes epiphytes), some semi-shrubs or even small trees and others climbers, perennial except in cold climates, it is the aerial area where the plant dies. The flowers are very diverse both in shape and size, and in color; they are unisexual, the male contains numerous stamens, the female has an inferior ovary with 2 or 4 branched stigmas. The fruit is a winged capsule containing a large number of tiny seeds. The leaves are asymmetrical and, like the flowers, differ greatly from one species to another, from variegated as in Begonia brevirimosa to bright green in Begonia ulmifolia.

3 basic groups can be distinguished, depending on the root:

• Fibrous root begonias as Begonia semperflorens and its hybrids, it is usually cultivated inside. It supports the direct sun, although not the frosts. As its name indicates, it blooms for almost the whole year.
• Rizomatous begonias, like B. rex, very appreciated for her foliage.
• Begonias tuberosas, B. x thuberhybridaWith very big flowers.

Some species of begonias are grown for their attractive foliage rather than their flowers: they are very beautiful

• The species B. Masoniana Irmsch. ex Ziesenh.

It has beautiful, finely wrinkled, heart-shaped leaves, yellowish-green in color and with a very marked dark brown interior pattern.

• B. metallic W.G.Sm. of an elegant dark green foliage almost metallic, hence its name.
• B. Imperialis Lem. has emerald green leaves or bronze with a soft velvety look.

Different groups have different growing requirements, but most require warm temperatures, light shade (few tolerate direct sun), well-draining soil that is not constantly wet, but also not allowed to dry out completely. Many of the species grow and flower throughout the year, although tuberoses normally have a dormant period during which the tubers can be removed and stored in a cool, dry place.

Most species are easily propagated by division or stem and leaf cuttings, or even fragments of a leaf. Especially members of the rhizomatous group.

Diseases: Red spider mites, powdery mildew.

Taxonomy

Sections

• Begonia sect. Coelocentrum
• Begonia sect. Donaldia
• Begonia sect. Doratometra
• Begonia sect. Enita
• Begonia sect. Lepsy
• Begonia sect. Monopteron
• Begonia sect. Nerviplacentaria
• Begonia sect. Parvibegonia
• Begonia sect. Peltaugustia
• Begonia sect. Rostrobegonia