PTTB-600: A Benchmark and Reproducibility Dataset for Long-Tail Plant Taxonomic Knowledge

PTTB-600 is a reproducibility dataset for evaluating large language models on long-tail plant taxonomic knowledge. It contains the complete Chinese-language question bank, answer key, answer-free evaluation set, model responses, item-level score matrix, model-level and dimension-level results, English figures, analysis scripts, and a data dictionary. The benchmark comprises 200 general questions, 300 ordinary specialized questions, and 100 long-tail fill-in questions evaluated across 31 models or run modes under closed-book conditions. Chinese question stems and item-linked fields are retained as primary research data.