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(Begonia family)


Five genera comprising some 920 species of herbs and sub-shrubs occur naturally in the tropics.

Members of the genus Begonia L. are commonly cultivated in temperate regions as house, greenhouse, and border plants.

There is evidence that some species are able to elicit dermatitis.

Begonia L.
Elephant's Ears

About 900 species have been described. They are natives of tropical and sub-tropical regions, especially in the Americas.

Several are grown for their colourful flowers and ornamental leaves. For horticultural purposes, the begonias may be divided into four groups: bulbous, tuberous, rhizomatous, and fibrous-rooted. Cultivars of Begonia semperflorens Link & Otto, a fibrous-rooted species, and Begonia rex Putz., a rhizomatous species, as well as hybrid tuberous begonias of complex parentage are commonly offered by seed merchants and nurserymen.

The name elephant's ears refers to the shape of the leaves of the plants. The term is also used for various members of the family Araceae that are also commonly grown as house and greenhouse plants. Members of these two families may however be distinguished very easily by their flowers.

Hjorth (1968) reported eight positive patch test results from 77 tests with unspecified members of this genus.

A man who picked begonias and other plants developed allergic contact dermatitis to benomyl, a systemic fungicide that had been used on the plants (van Ketel 1976). It is not clear from the report whether the patient was tested with a pure sample of benomyl or with Benlate®, the commercial formulation containing technical grade benomyl.

Begonia x erythrophylla hort. ex Hérincq
(syn. Begonia x feastii hort.)
Beefsteak Begonia, Kidney Begonia

[Information available but not yet included in database]

Begonia grandis Dryander ssp grandis
(syns Begonia discolor R. Br., Begonia evansiana Andrews, Begonia grandis Dryander ssp evansiana Irmscher, Diploclinium evansianum Lindl.)
Hardy Begonia, Evans' Begonia, Japan-Begonie

[Information available but not yet included in database]

Begonia rex Putz.
(syn. Begonia longiciliata C.Y. Wu)
Rex Begonia

One positive patch test reaction was observed from 33 tests with this species (Agrup 1969).

Begonia semperflorens Link & Otto
Fibrous-Rooted Begonia

Six positive patch test reactions from 101 tests with this species were reported by Agrup (1969).


  • Agrup G (1969) Hand eczema and other hand dermatoses in South Sweden. Acta Dermato-Venereologica 49(Suppl 61): 1-91
  • Hjorth N (1968) Personal communication to Mitchell JC. In: Mitchell J, Rook A (1979) Botanical Dermatology. Plants and plant products injurious to the skin, p. 130. Vancouver: Greengrass
  • van Ketel WG (1976) Sensitivity to the pesticide benomyl. Contact Dermatitis 2(5): 290-291
  • [ + 2 further reference not yet included in database]

Richard J. Schmidt [Valid HTML 4.01!]

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