https://purpletreehouse.blogspot.com/2023/11/poetry-form-week-96-humor-week-111yams.html

山药，中药材名。本品为薯蓣科植物薯蓣的干燥根茎。11～12月采挖，切去根头，洗净泥土，用竹刀刮去外皮，晒干或烘干，即为毛山药

Dioscorea opposita Thunb lockman, or shan yao