Comments
Liverworts are related to mosses; they grow on the bark of trees in areas of high humidity. Liverworts contain sesquiterpene lactone allergens. Occupational allergic contact dermatitis has been described in woodcutters, fallers, and other forest workers. Affected workers are often allergic to lichens, as well. Some affected workers have to change occupations. [Marks, p. 252-3]