Pollen from some trees are very allergenic. The distribution of allergenic trees differs among geographical areas.

For example, Betula (Birch) is found in Central and North of Europe but is seldom in Spain (just in the North-West). By contrast, Olea (Olive tree) is found widely distributed in the Center, and especially in the South of Spain. Cupressus spp. (Arizona and Italian cypress) pollen is also an important cause of allergy in the South of Europe, as well as Platanus spp. (Plantain) in some cities like Madrid.

By clicking on the draw you may access to the pollen counts of the allergenic plants in different cities of Spain.