The group consists of the scientific papers of J. Lloyd Williams, reflecting his interest and vocation in the field of botany, comprising correspondence, 1892-1942; diaries, 1871-1920; field notes, 1887-1934; botanical terms, [1890x1940]; and lectures, [1905x1937].
Notebooks, each containing entries, often sparse, of a varied nature. They reflect the wide range of interests displayed throughout J. Lloyd Williams's papers, but mainly relate to music. The subjects include the history of Welsh music, folk music, Y Cerddor and the National Council of Music, his own compositions and memoirs, broadcasting and education. Entries relating to botany are also included, especially in items numbered 23-28.