University of Isfahan Taxonomy and Biosystematics 3115-9001 18 67 2026 02 01 Integrative biosystematics study of Seseli staurophyllum Rech.f. (Apiaceae), an endemic gypsophyte from Iran 15 30 30254 10.22108/tbj.2026.147918.1329 EN Fatemeh Rabizadeh Assistant Professor, Department of Biology, Farzanegan Campus, Semnan University, Semnan, Iran Journal Article 2025 12 26 <em>Seseli staurophyllum</em> Rech.f. (≡ <em>Lomatopodium staurophyllum</em> (Rech.f.) Rech.f.) is a narrowly distributed endemic species of Apiaceae, restricted to gypsum–marl and serpentine substrates in northeastern Iran. Formerly treated as the sole representative of the monotypic genus <em>Lomatopodium</em>, this taxon exhibits distinctive morphological traits and a high degree of ecological specialization. Despite its taxonomic and ecological significance, comprehensive biosystematics studies integrating morphology, micromorphology, and habitat characteristics have remained limited. In this study, fresh field material and herbarium specimens were examined to document vegetative morphology, micromorphological structures, and ecological parameters. The species develops woody, highly branched subterranean stems covered with waxy and farinose layers, bears one to two pairs of cuneate to flabellate leaves, and produces compound umbels with predominantly two to three rays. Scanning electron microscopy revealed specialized epidermal features, including persistent epicuticular wax, sunken stomata, and simple multicellular trichomes, which are commonly associated with drought tolerance in gypsum-adapted plants, high solar radiation, and edaphic stress. Ecological analyses confirm that <em>S. staurophyllum</em> is strictly confined to gypsum-rich and serpentine substrates across a limited elevational range in northern Iran. The updated distributional data, assessment of habitat specialization, and identification of key adaptive traits presented here provide essential information for taxonomic clarification, ecological interpretation, and conservation-oriented studies of gypsum-associated endemic plants.<br />  https://tbj.ui.ac.ir/article_30254_dab438e38efe465c6f06767a04ddbf2b.pdf