Begonia

''Begonia'' is a genus of perennial flowering plants in the family Begoniaceae. The genus contains more than 2,000 different plant species. The Begonias are native to moist subtropical and tropical climates. Some species are commonly grown indoors as ornamental houseplants in cooler climates. In cooler climates some species are cultivated outside in summertime for their bright colorful flowers, which have sepals but no petals.

Description

With 2,002 species, ''Begonia'' is one of the largest genera of flowering plants. The species are terrestrial (sometimes epiphytic) herbs or undershrubs, and occur in subtropical and tropical moist climates, in South and Central America, Africa, and southern Asia. Terrestrial species in the wild are commonly upright- stemmed, rhizomatous, or tuberous. The plants are monoecious, with unisexual male and female flowers occurring separately on the same plant; the male contains numerous stamens, and the female has a large inferior ovary and two to four branched or twisted stigmas. In most species, the fruit is a winged capsule containing numerous minute seeds, although baccate fruits are also known. The leaves, which are often large and variously marked or variegated, are usually asymmetric (unequal-sided).

File:BegoniaBrevirimosa.jpg, ''Begonia brevirimosa''
File:B. aconitifolia JV 250x242.jpg, ''Begonia aconitifolia''
File:Begonia 1.jpg, A flowering begonia
File:Yellow begonia.jpg, Begonia cultivars come in many different colors, such as yellow
File:Begonia 'Parviflora' Leaf 3000px.jpg, A begonia leaf
File:Begonia blossoms maleandfemale.jpg, A pair of blossoms, male and female
File:Nautilus leaf begonia Surreybrooke farm 2012-07-1.jpg, A nautilus-leaf form of begonia
File:Begonia 0.jpg, Begonia
File:Begonia leaf.jpg, Begonia leaf
File:Cracklin Rosie begonia 02.jpg, Cracklin Rosie begonia
File:Cracklin Rosie begonia 03.jpg, Cracklin Rosie begonia
File:鐵十字秋海棠 - 溪頭自然教育園區 Begonia masoniana - Xitou Nature Education Area, Taiwan 20220309210209 01.jpg, Leaf of ''Begonia masoniana''

Taxonomy

The genus name ''Begonia'' was coined by Charles Plumier, a French patron of botany, and adopted by Linnaeus in 1753, to honor Michel Bégon, a former governor of the French colony of Saint-Domingue (now Haiti).

Phylogeny

The following phylogenetic tree shows the relationships among sections of the genus ''Begonia''.

Species

Selected species:

* '' Begonia coccinea''
* '' Begonia foliosa''
* '' Begonia grandis'' Dryand.
* ''Begonia obliqua''
* '' Begonia cucullata''

Cultivation

The different groups of begonias have different cultural requirements, but most species come from tropical regions, so they and their hybrids require warm temperatures. Most are forest understory plants and require bright shade; few will tolerate full sun, especially in warmer climates. In general, begonias require a well-drained growing medium that is neither constantly wet nor allowed to dry out completely. Many begonias will grow and flower year-round except for tuberous begonias, which usually have a dormant period. During this dormant period, the tubers can be stored in a cool, dry place. Begonias of the semperflorens group (or wax begonias) are frequently grown as bedding plants outdoors. Wax begonias are very attractive, they adapt well when brought inside the house for overwintering and can live up to 4-5 years.

A recent group of hybrids derived from this group is marketed as "Dragonwing" begonias; they are much larger both in leaf and in flower. Tuberous begonias are frequently used as container plants. Although most ''Begonia'' species are tropical or subtropical in origin, the Chinese species '' B. grandis'' is hardy to USDA hardiness zone 6 and is commonly known as the "hardy begonia". Most begonias can be grown outdoors year-round in subtropical or tropical climates, but in temperate climates, begonias are grown outdoors as annuals, or as house or greenhouse plants.

Most begonias are easily propagated by division or from stem cuttings. In addition, some can be propagated from leaf cuttings or even sections of leaves, particularly the members of the rhizomatous and rex groups.

Horticultural nomenclature

The nomenclature of begonias can be very complex and confusing. The term 'picotee' refers to edging on the petals that is in contrast to the color of the main petal if the colors blend. If they do not, then the term 'marginata' is used, but sometimes these terms are used simultaneously. 'Non-Stop' refers to a camellia tuberous hybrid that under certain conditions will bloom 'non-stop' all year round.

Cultivar groups

Because of their sometimes showy flowers of white, pink, scarlet, or yellow color and often attractively marked leaves, many species and innumerable hybrids and cultivars are cultivated. The genus is unusual in that species throughout the genus, even those coming from different continents, can frequently be hybridized with each other, and this has led to an enormous number of cultivars. The American Begonia Society classifies begonias into several major groups:

* Cane begonia forms tough, bamboo-like canes
* shrub-like
* tuberous
* rhizomatous
* semperflorens (wax or fibrous rooted begonias)
* Rex
* trailing-scandent
* thick-stemmed
For the most part, these groups do not correspond to any formal taxonomic groupings or phylogeny, and many species and hybrids have characteristics of more than one group or do not fit well in any of them.

AGM plants

The following is a selection from about 70 species, varieties and cultivars which currently hold the Royal Horticultural Society's Award of Garden Merit:-

* ''Begonia'' 'Benitochiba'
* ''Begonia dregei''
* ''Begonia foliosa'' var. ''miniata''
* ''Begonia'' 'Glowing Embers'
* ''Begonia grandis'' subsp. ''evansiana''
* ''Begonia grandis'' subsp. ''evansiana'' var. ''alba''
* ''Begonia'' 'Green Gold'
* ''Begonia listada''
* ''Begonia luxurians''
* ''Begonia masoniana''
* ''Begonia metallica''
* ''Begonia solananthera''
* ''Begonia soli-mutata''
* ''Begonia sutherlandii''

Culture

The cultivar 'Kimjongilia' is a floral emblem of North Korea.

Most begonias are sour to the taste, and some people in some areas eat them. This is safe in small amounts but potentially toxic in large quantities due to the prevalence of oxalic acid in the tissues.Laferrière, Joseph E. 1990. On the edibility of begonias. Begonian 57:175.

References

External links

*

American Begonia Society

W. S. Hoover et al. 2004, Notes on the geography of South-East Asian Begonia and species diversity in montane forests

Phylogenetic Relationships of the Afro-Malagasy Members of the Large Genus ''Begonia'' Inferred from trnL Intron Sequences

A Phylogeny of ''Begonia'' Using Nuclear Ribosomal Sequence Data and Morphological CharactersBegonia L. Plants of the World OnlineAccepted species Plants of the World Online

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Cucurbitales genera
Garden plants