Gypsum soils play a critical role in plant distribution. The Irano-Turanian region has been reported as rich in gypsophile species. Despite this richness, the ecological and floristic studies focusing on gypsum soils in Iran remain scarce. Building upon the research conducted by Pérez-García et al. (2018) using the floristic data who reported 301 gypsophyte and gypsocline species from the Iranian territory, our study delved into the distribution of specific species listed in the 2018 checklist, examining their distribution in northeastern Iran through the utilization of existing data in the literature and also field investigation on their distribution and soil physical and chemical properties. Our findings challenge the classification of certain endemic species, including Anabasis firouzii, Atraphaxis intricata, Colutea gifana, and Psephellus galactochrous, previously categorized as gypsoclines or gypsophytes, which are not observed in the gypsum soils and they are mainly calciphytes. We have also classified certain species based on their distribution into gypsovags, including species such as Astragalus citrinus, Astragalus podolobus, Krascheninnikovia ceratoides, Matthiola farinosa, Astragalus verus, Dendrostellera lessertii, and Euphorbia bungei, previously identified as gypsoclines. Additionally, species like Sclerorhachis platyrachis, Hedysarum monophyllum, and Cleome turkmena, which were introduced as gypsophytes, have also been found in other non-gypsum soils with high abundance. Given Iran’s remarkable species and habitat diversity, we strongly advocate for more extensive and precise studies in this field. It is crucial to note that most of these species are endemic and specific to certain regions. Therefore, undertaking comprehensive ecological studies is essential to revise the classification of gypsophytes in Iran and gain an indepth understanding of the intricate nature of gypsum soils, ultimately facilitating the conservation and restoration efforts for these complex ecosystems.

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