Article

The situation of the hemerophytic flora of Friuli-Venezia Giulia in its adventitious, autapophytic and deuterapophytic components is here considered. For each of these the family composition, life and growth form spectrum, chorological spectrum, and subdivision into phytosociological classes are studied. The actual situation is compared to that before 1945 and the main reasons of the changes occurred in the emerophytic flora are discussed. A "diffusion index " , expressing the capability of an adventitious spec ies to spread within a territory is suggested. Fina\ly the up-to-date list of the adventitious species found in the region after 1945 is provided.