POWO follows these authorities in synonymising this name:
Govaerts, R. (2003). World Checklist of Monocotyledons Database in ACCESS: 1-71827. The Board of Trustees of the Royal Botanic Gardens, Kew. [Cited as Oncidium.]
Pridgeon, A.M., Cribb, P.J., Chase, M.C. & Rasmussen, F.N. (2009). Epidendroideae (Part two). Genera Orchidacearum 5: 1-585. Oxford University Press, New York, Oxford. [Cited as Tolumnia.]
Other Data
Other Kew resources that provide information on this taxon:
The International Plant Names Index and World Checklist of Vascular Plants 2023. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/