Life forms and chrotypes of unwanted weedy plants in the main parks of Tehran

City of Tehran because of its specific location in southern slopes of central Alborz Mountains and at the edge of Dasht-e-Kavir is interesting to study in terms of its vegetation. In this paper, germination traits and life history of the weeds are studied in a number of parks in Tehran. Study of the vegetation of plates has performed by minimal area. The total numberber of identified plants are 52 Species from 43 genus and 23 families. Poaceae and Compositae represent as the mostabundant families. Chrotype is recognized by the use of various Flora. Therophytes with 44.2% (23 species) are the most abundant lifeforms. 17 species (32.6% of the total species) are cosmopolite withworldwide distribution and the other species are pluriregional.