Tarenaya spinosa (Jacq.) Raf. (Cleomaceae): a new addition to the naturalized alien flora of Iran

We report the first record of Tarenaya spinosa (Jacq.) Raf. (spiny spider flower) as a new addition to the naturalized alien flora of Iran. Spiny spider flower is native to South and Central America and widely naturalized in the paleo-tropics (south Africa and Asia). This species was intentionally introduced to Iran in the last decade of the XX century and cultivated as an ornamental plant due to its large, peculiar, and colorful flowers. It escaped from cultivation and gradually increased its alien range in the surrounding areas, by seeds, without any direct human intervention. The UNESCO-world-heritage site Hyrcanian forests (northern Iran) includes a unique forest ecosystem which is potentially threatened by the naturalization of many alien and invasive species including this new recorded alien. Considering the potential negative impacts of this new alien species on the native biodiversity and its high reproductive potential and spread capacity, we highlight the importance of preventing new introductions, and prioritizing practices for eradication and control before it could become widespread and unmanageable.