Phytoliths are extensively utilized as an archaeobotanical indicator in paleovegetation reconstruction and environmental archaeology. Over the past two decades, numerous phytolith morphotypes, particularly those exhibiting diagnostic morphological features and over representative of source plants at the genus and species levels, were discovered and reported. These advancements have significantly contributed to phytolith-based vegetation reconstruction on different timescales, enhanced our understanding of prehistoric plant utilization, and elucidated cultivation and domestication processes of key crops in ancient agriculture. However, there are still inconsistencies and misunderstandings regarding the morphological characteristics of diagnostic phytoliths in various plant groups. This review highlighted the standardization in the classification and description of phytolith morphotypes, and summarized the advancements in phytolith morphology research over the past two decades. Morphological illustrations of diagnostic phytoliths from various plant groups, particularly key crops and their relatives from dryland and rice agriculture in East Asia, were presented as references for phytolith identification and application. Finally, this review proposes future directions for phytolith morphological studies, emphasizing the comprehensive consideration of anatomical structure and morphometric parameters, as well as the need for extensive research on modern plant phytoliths and control experiments on phytolith growth.
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