Data from: A morphometric analysis of starch granules from two Dioscorea species

Dioscorea L. is a genus comprised of over 600 species, many of which
possess edible tubers that are commonly referred to as yams. While
Dioscorea is a significant crop across the globe, it holds a unique
cultural significance to the people of Tonga in western Polynesia.
Presently, Dioscorea is known for its essential role in festivals and
ceremonies, as well as for its nutritional contribution in Tongan diets.
To understand and to assess the significance of Dioscorea in the distant
past, however, archaeologists rely on plant residues (e.g. starch
granules) preserved on ancient tools. This study provides the necessary
first step in archaeological starch analysis by examining granule
morphometrics of two culturally significant Dioscorea species, D. alata
and D. bulbifera from Tonga. Tubers from three individuals of each species
were collected on the island of Vava’u and processed for starch granule
extraction and analysis. Morphometric characters, including two novel that
describe shape (eccentricity ratio and hilum angle), were measured on 300
granules per species. When statistically compared, these novel characters
allow D. alata and D. bulbifera to be readily distinguished from one
another, and, therefore increase confidence in assigning archaeological
granules to a specific taxon.

薯蓣属（Dioscorea L.）是包含600余个物种的植物类群，其中多数物种具有可食用块茎，这类块茎通常被称为山药（yam）。尽管薯蓣属植物在全球范围内均为重要作物，但对于西波利尼西亚汤加地区的民众而言，它拥有独特的文化意义。如今，薯蓣属植物在汤加社会中以其在节庆与仪式中的核心作用，以及对汤加饮食的营养贡献而被广泛认知。然而，若要了解并评估远古时期薯蓣属植物的重要性，考古学家需依赖古代工具上留存的植物残体（例如淀粉粒）。本研究针对汤加境内两种具有重要文化意义的薯蓣属物种——参薯（Dioscorea alata，D. alata）与黄独（Dioscorea bulbifera，D. bulbifera）的淀粉粒形态计量学特征展开分析，为考古淀粉分析提供了必要的前置研究基础。研究人员在瓦瓦乌岛（Vava’u）采集了每个物种各3个个体的块茎，随后对其进行淀粉粒提取与分析处理。本研究为每个物种选取300个淀粉粒，对其形态计量学特征进行测量，其中包含两项用于描述形状的全新指标：偏心率（eccentricity ratio）与脐点角（hilum angle）。经统计学对比分析后，这两项全新指标可轻松区分参薯与黄独的淀粉粒，从而提升了将考古发掘所得淀粉粒归属至特定分类群的可信度。