The site of Sialk, comprising the older North Mound and younger South Mound, is among Iran’s most significant archaeological complexes. The Sialk Reconsideration Project has documented and preserved all material categories for research, including botanical remains that inform reconstructions of past subsistence and human–plant interactions. During the project’s second field season in 2023, a pit rich in macro-botanical remains was discovered in the Iron Age occupation layers. It was the only context from that campaign to yield substantial plant remains.

This study presents the taxonomic identification, typological characterization, and archaeobotanical analysis of the assemblage, comparing the Iron Age evidence with that from Sialk’s Neolithic strata. The Iron Age pit yielded several cereal taxa, including Triticum spp., Triticum aestivum, Triticum monococcum, Triticum dicoccon, and Hordeum vulgare, alongside abundant charred Vitis vinifera seeds. A nutshell of wild Pistacia atlantica was also identified. Neolithic contexts, by contrast, yielded different plant taxa, including a distinctive “New Type” Triticum, Triticum dicoccon, and weeds such as Galium sp..

Comparison with Iron Age Pit 135 suggests possible changes in plant use and subsistence practices. The Iron Age assemblage is dominated by domesticated cereals and charred grape seeds, whereas the published Neolithic assemblage contains a wider range of identified wild taxa and cereal-processing remains. These differences may reflect changes in plant use and processing; however, the limited Iron Age evidence and differences in dataset reporting preclude broader conclusions about Iron Age Sialk’s subsistence economy. The association of grape seeds with strainer-type vessels suggests possible grape processing, but wine production or other grape-based products remain hypotheses requiring further investigation. Plant remains processing in the Iron Age appears to have occurred outside domestic spaces, unlike the Neolithic, when it took place in residential areas. Drier Neolithic conditions or the use of barley primarily as livestock fodder may have influenced changing crop choices and agricultural strategies.