The breeding history of begonias

The breeding history of begonias

Begonia grandis

Early Discovery & Naming
Begonias were described for the first time in 1690 by a French botanist, Charles Plumier, who named them after a fellow French botanist, Michel Bégon. It was the first time a plant was named to honour another botanist, and this later became a tradition when naming a new plant. Other names had been used before for begonias, but eventually the name was set when Linnaeus used it in 1753 in his Species Plantarum. Earlier descriptions under a different named include the Mexican species B. gracilis, then named ‘Totoncaxoxo Coyollin’ in 1557 by Hernandez. Begonia grandis is even thought to have been cultivated in China since the 14th century! Richard Pearce, a British plant hunter, rediscovered begonias in South America in the 1860s.

The first living begonia only reached Europe in 1777, when William Brown sent Kew Gardens a specimen of begonia minor. By 1847, 70 to 80 species were already in cultivation. Hybridisation began in the early 1800s, resulting in cultivars like ‘ricinifolia’, ‘erythrophylla’ and ‘phyllomaniaca’.

Begonia Groups

The breeding history of begonias

Begonia roezlii

Begonia semperflorens cultorum
Begonia x semperflorens, otherwise known as wax begonias or bedding begonias are hugely popular and are one of the most common plants in commercial cultivation today, as they are such easy plants to grow. In 1821, the origin species of the B. x semperflorens hybrids, B. cucullata, was introduced by accident along with a plant shipment from Brazil to the Berlin Botanical Garden. A hidden seed germinated in the soil in which the plants were growing and formed the base of today’s bedding begonias! In 1878, a cross between B. cucullata var. hookeri and B. schmidtiana, both of Brazilian origin, resulted in the first interspecific hybrid within this group. This hybrid was of medium stature, with glossy foliage and pale pink flowers. During the early 1880s, a third species entered the mix, B. roezlii, which brought deeper pink and even red flowers. A further chance development happened during the 1890s when a bronze-leaved mutant arose in a garden in France and was then used to develop all bronze-leaved begonias.

The breeding history of begonias

Begonia gracilis

Many other chance mutations during the 1800s led to variegated varieties, the first appearing in 1886. In 1894 the first F1 hybrid, ‘Erfordia’, was released commercially by Benary, this was also the first commercial F1 hybrid altogether. It proved to be uniform & showed good hybrid vigour, being very floriferous and tolerant to adverse weather conditions. Unfortunately these first hybrids were almost sterile, so breeders selected fertile plants, trying to create an F2 generation, as well as backcrossing the F1s with the parents. This breeding method resulted in polyploidy and single triploid plants. Eventually the first true tetraploid hybrid appeared in 1895, ‘Gracilis’. These tetraploids were floriferous and compact in habit. While the first ‘Gracilis’ types were fertile, their offspring were not: back crossing with B. cucullata var. hookeri created triploid sterile plants. Fertile tetraploids were nonetheless obtained. Eventually in 1909 through inbreeding and intercrossing, an F1 tetraploid hybrid cultivar called ‘Primadonna’ was produced, with excellent hybrid vigour.

At the turn of the 20th century a cross between B. minor  and the other existing hybrids produced a semi double flowering cultivar, B. ‘Bijou de Jardin’. The first fully double-flowered cultivar did not surface until 1934 in Sweden: B. ‘Gustav Lind’, whose parentage lies in B. foliosa var. miniata. Around this time the first picotee and bicoloured varieties also emerged onto the global market.

Many of the thousands of cultivars available worldwide are often created by crossing together each new variety with the existing hybrids. Many of the original parents were never used again. B. cucullata is a prime example of this: since the first initial cross with this plant to create the group, it has not been used again in the breeding of B. x semperflorens.

The breeding history of begonias

Begonia socotrana

B. x hiemalis
The name begonia x hiemalis was given by Karl Albert Fotsch in 1933 to all begonia cultivars resulting from the crosses between various cultivars of begonia x tuberhybrida and begonia socotrana. The first B. x hiemalis cultivar, ‘John Heal’, was created in 1883, from a cross between B. x tuberhybrida ‘Viscountess Doneraile’ and B. socotrana. Since 1883 many cultivars have been introduced. These cultivar names often end up as the common name for this group of Begonias, such as ‘Elatior’, ‘Baardse’ and in the USA they are called ‘Holland Begonias’. They are also sometimes named ‘House Begonias’.

The hiemalis begonia group did not have much commercial success until 1955, as they were difficult to grow. In 1955 a German nurseryman developed a greatly improved series of the hiemalis group named after him, the ‘Rieger’ series. These cultivars were easy to grow, longer flowering and were more resistant to diseases such as mildew. The Rieger series begonias were the result of a cross between B. ‘Bertinii compacta Leuchtfeuer’ and B. socotrana. The resulting hybrids had to be produced vegetatively as they have 26, 27 or 28 long chromosomes from the tuberous tetraploid parent and 14 short chromosomes from B. socotrana, resulting in the progeny being triploid and thus sterile.

The breeding history of begonias

Begonia dregei

B. x cheimantha
Begonia x cheimantha is a hybrid from the species B. dregei, originating in South Africa and B. socotrana, coming from the Yemeni island of Socotra. The cross was made in 1891 in France by Lemoine and named B. ‘Gloire de Lorraine’. This cultivar was not hugely successful, because it was tricky to grow. Once it was released onto the market, it was heavily worked on by breeders. The plants were self pollinated, backcrossed with their parents and improved by bud sports. These cultivars became collectively known as ‘Christmas Begonias’ and in 1940 the director of horticulture at the New York Botanical Gardens classified these hybrids as B. x cheimantha.

The hybrid was also backcrossed to Begonia socotrana twenty years later. Much of the breeding of Christmas Begonia is currently done in Scandinavia. The variety B. ‘Gloire de Lorraine’ is often referred to as one of the finest hybrid begonias ever raised. ‘Gloire de Lorraine’ was used as a parent in many of the subsequent hybrids and varieties, such as B. ‘Glory of Cincinnati’ and B. ‘Konkurrent’, both of which have a doubled chromosome number. When they were backcrossed to the diploid B. socotrana, they gave sterile triploids with a longer flowering period and better shelf life.

The breeding history of begonias

Begonia pearcei

B. x tuberhybrida
Begonia x tuberhybrida’s origins lie in South America along the Andean mountains. B. x tuberhybrida has several parents including B. boliviensis and B. pearcei. However it is British plant hunter Richard Pearce’s introduction of B. veitchii in 1866 that triggered a hybridisation frenzy in tuberous begonias. Pearce found this species in the Peruvian Andes around Cuzco, not far from the later discovered Machu Picchu, the lost city of the Incas.

John Seden, of Veitch Nurseries, was at the forefront of the initial hybridisation work, using B. boliviensis, B. cinnabarina, B. clarkei, B.pearcei, and B. veitchii. The first hybrid to come out of this programme was begonia ‘Sedenii’ and was described in 1870 as being a rich magenta colour with large flowers. This first introduction on the market encouraged many other hybridisers throughout Europe to develop the group further. Over the next four years a breakthrough was achieved with the first true white-flowered tuberous begonia hybrid, ‘White Queen’. This cultivar was the result of crossing B. ‘Sedenii’ and the South African, white-flowered species B. dregei.

There were many other breeders and growers at this time improving the tuberous hybrid group, but one in particular, Victor Lemoine, was influential. Lemoine was based in France and his begonia work was principally based on B. ‘Sedenii’, B. veitchii and B. pearcei. He produced the first yellow-flowered cultivar and was also the first breeder in the 1870s to develop a double-flowering tuberous begonia, ‘Gloire de Nancy’. The breeding and hybridising of the tuberous begonias was developing so rapidly that by the 1880s only a few wild species were being used, instead further selection of existing hybrids prevailed. As a result of this intense breeding activity, the group B. x tuberhybrida has been divided into 17 sub groups differentiating between pendulous, large-flowered, multiflora, large double, small double and many other distinctive characteristics.

Tuberous begonias were thought to be tropical plants and kept in hot glasshouses. However their high Andean origin gives them a good tolerance to cold. In summer 1875 B. ‘Sedenii’ was first used outdoors as a bedding plant. Only one year later begonias were already every gardener’s favourite bedding plant!