Viola tricolor L. Violaceae 'Black Magic'. Heartsease. Distribution: Europe. Gerard (1633) writes that it is good for fevers especially for children and infants whose convulsions and fits of the falling sickness it is thought to cure' These are presumably the febrile convulsions of childhood which stop when the fever subsides, whatever one does. He also says it is good for chest conditions, itching all over, and ulcers and 'to cure the pains of the French disease [syphilis]'. It is approved for topical use in mild seborrhoeic dermatitis because of traditional use, in Europe, but a trial of a cream containing V. tricolor was no more effective than the base cream without ingredients. A child with glucose-6-phosphate dehydrogenase deficiency developed haemolysis ('favism') following oral administration. It also contains salicylates so should be used with caution (European Medicines Agency, Assessment report on Viola tricolor, November 2010).

A child with glucose-6-phosphate dehydrogenase deficiency developed haemolysis ('favism') following oral administration. It also contains salicylates so should be used with caution (European Medicines Agency, Assessment report on Viola tricolor, November 2010).