Peperomia matapalcoensis is a nomen novum for Acrocarpidium mexicanum, which in its turn was a nomen novum for Peperomia rotundifolia Schlecht. (Miquel 1843: 53). Miquel likely meant Peperomia rotundifolia ‘sensu Schlecht.’ because in the publication to which Miquel refers (Schlechtendahl & Chamiso 1831: 353) Peperomia rotundifolia ‘HBK’ is clearly mentioned. Duplicates of the concerning specimen, Schiede s.n. (B - destroyed), have been traced (PRC!, U!) and they indeed agree with Peperomia rotundifolia, hence Acrocarpidium mexicanum and Peperomia matapalcoensis are synonyms of the latter. For this reason the name Peperomia metapalcoensis cannot be given to a species represented by the paratype Fraser s.n., differing from Peperomia rotundifolia in the characters of leaves, stems and inflorescences. Another paratype, Wright 2262 from Cuba, was excluded by de Candolle (annotation G-DC specimen, 1901). De Candolle followed Dahlstedt who designated this collection as the type of Peperomia spathophylla.