The pollen calendar of Siena (Central Italy)

The atmospheric pollen count at Siena was carried out for 4 years (1978-1981) to determine the average quantity of airborn pollen and the families, genera or species which contribute to such pollen dispersal. The pollination period stretches from February to mid October. The highest pollination period is from May to July when the most important pollen producers are Poaceae, Urticaceae, Pinus, Quercus, Oleaceae and Castanea sativa. Also in March there are high pollen production values due to Cupressaceae, Corylaceae, Alnus and Ulmus.