The first official report of the alien species Bidens subalternans for the Iranian flora

In the present paper, a new alien species, namely, Bidens subalternans (Asteraceae), was found growing at the gardens in the Marvdasht and Eqlid located in Fars Province (Iran). This species is native to S. America, likely being introduced to Iran through international transport of goods, agricultural products or via barbed fruits attached to cloths or personal items (possibly from China or Europe). It may have initially entered southern Iran and subsequently spread to other regions, especially Northern provinces, through fruit transportation. Mature plant specimens, along with capitulum and achenes, were collected from its growth sites in ۲۰۲۵. Species identification was based on detailed morphological studies and using authoritative taxonomic keys by the flora Europea. This species bears considerable morphological resemblance to B. bipinnata, which has been more frequently reported in Iran, and can be distinguished mainly by leaf shape, the number and angle of the pappus awns on the fruit, and capitulum characteristics. The current distribution of this species in Iran is limited to gardens, particularly pomegranate orchards, where it occurs as a weed. Phenological observation in its natural habitat indicated that, the plant life cycle in these gardens begins with germination in May-June, while flowering and fruiting occur mainly during the summer. Further studies are recommended to accurately determine its distribution range and assess potential ecological risks.

کلیدواژه ها:

Asteraceae ، Beggarticks ، dispersal ، habitat ، invasive plant ، Weeds