Pollen production of the genus Cupressus

The study of potential pollen emission in the genus Cupressus was carried o ut in the city of Cordoba (Spain). Pollen production of 227 trees of the re presented species of Cupressus in the area (Cupressus sempervirens, C. macr ocarpa and C arizonica) was studied by counting the number of pollen grains per flower, the number of Rowers per branch, and the number of branches pe r m(2) of surface area. Total surface area was estimated by considering the shape of the tree as a cone and estimating the average height and radius o f each species. Results indicated that there was little variation in the nu mber of pollen grains produced by a flower within each species. Equally, th ere were few differences in the number of grains per Rower among the specie s, although C. ur arizonica had slightly fewer than the other species becau se it possessed fewer stamens per flower. However, there were clear differe nces in the number of flowers per branch, with C. macrocarpa having the hig hest floral density, considerably lower in C. arizonica and even lower in C . sempervirens. All of this indicates that the pollen contribution of C. ma crocarpa to the atmosphere is far greater than that of C arizonica and C. s empervirens. The results indicate a different potential emission in each sp ecies, and this must be taken into account when determining the quantity of pollen present in the atmosphere. The maximum amount of pollen grains that one individual can spread is provided in this study and would provide usef ul data in the development of an airborne forecasting system.