| Begonia | |
|---|---|
| | |
| Begonia obliqua | |
| Scientific classification | |
| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Cucurbitales |
| Family: | Begoniaceae |
| Genus: | Begonia L. |
| Type species | |
| Begonia obliqua L. | |
| Species | |
| | |
| Range of the genus Begonia | |
| Synonyms | |
List
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Begonia is a genus of perennial flowering plants in the family Begoniaceae. The genus contains more than 2,000 different plant species, distributed primarily across tropical and subtropical regions of Africa, Asia, and Central and South America, with Africa considered the center of origin. [1] Some species are commonly grown indoors as ornamental houseplants in cooler climates, or cultivated outside in summertime for their bright colorful flowers, which have petals but no sepals.
With 2,000+ species, Begonia is one of the largest genera of flowering plants. [2] [3] 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. Flowers come in all colors other than blue, and range in size from tiny individual blossoms to blooms the size of dinner plates. [4] 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 such that their left side and right side are different sizes. The plants vary in size from less than a foot to the recently discovered Begonia giganticaulis which can exceed twelve feet (3.6 meters) in height.
The genus name Begonia was coined by Charles Plumier, a French monk and botanist after discovering six new species in the Antilles, which he named Begonia to honor Michel Bégon, a former governor of the French colony of Saint-Domingue (now Haiti). The first time the name Begonia was used in print was in 1700, in a publication by Joseph Pitton de Tournefort. In 1753, Carl Linnaeus merged the original six species into one ( Begonia obliqua ). It was published in Species Plantarum and the name has been used ever since. [1]
The following phylogenetic tree shows the relationships among sections of the genus Begonia. [5]
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Selected species: [6]
The different groups of begonias have different care 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. [7]
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.
To describe the flower-shape of a begonia, the following abbreviations are sometimes used: [8]
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 is the International Cultivar Registration Authority for Begonia, and classifies them into several major groups [10] :
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.
The following is a selection from about 70 species, varieties and cultivars which currently hold the Royal Horticultural Society's Award of Garden Merit: [12]
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. [27]
In floriography begonias represent a warning, "we are being watched," "this must end," [28] "be careful," and/or "take heed." [29]