Gomphrena serrata Linnaeus (1753: 224) ≡ Xeraea serrata (L.) Kuntze (1891: 545). Neotype (designated by Mears 1980: 86–87):— MEXICO. Vera Cruz, 1731, Houstoun s.n., (BM000522330!, image available at: https:// data.nhm.ac.uk/record/ec9fffe8-f7f4-4dcd-9471-641c4922d956/20929). = Gomphrena decumbens Jacquin (1804: 41–42) ≡ Xeraea decumbens (L.) Kuntze (1891: 545). Lectotype (here designated):—[Icon] Tab. 482 in Plantarum rariorum horti caesarei Schoenbrunnensis descriptiones et icones (Jacquin 1804: T. 482, available at: https://www.biodiversitylibrary.org/page/273005). Typification of the name Gomphrena decumbens:— The protologue of Gomphrena decumbens (Jacquin 1804: 41–42) consists of a diagnosis (“ Gomphrena caulibus decumbentibus, hirsutis; foliis ovatis;capitulis subovatis, sessilibus ”), a detailed morphological description, and an illustration (T. 482), which can be considered as part of the original material for the name. However, the origin of the specimens consulted is unknown [Jacquin (1804) reported “ Patriam ignoro ”], and no information about the collector or the number of collection was provided. Jacquin’s herbarium and type are preserved at AWH, B, BM, CGE, H, JE, LINN, LIV, OXF, and UPS (see HUH-Index of Botanists 2013), but no specimen which can be considered as part of the original material for G. decumbens was traced. Fortunately, there is the illustration No. 482 which is very good including a colored plant with magnifications of androecium, gynoecium, fruit, and one seed. This drawing is here designated as the lectotype of G. decumbens according to the Arts. 9.3 and 9.4 of ICN. To be noted that many infraspecific names were published in the past under Gomphrena decumbens. As far as we have been able to check, none of these names appears to refer to what we consider here as G. caxcana. Anyway, we argue for a revision of the taxonomy and nomenclature of G. decumbens.

Published as part of Sandoval-Ortega, Manuel Higinio, Rodríguez-Pérez, Emmeth Josafath & Zumaya-Mendoza, Silvia, 2025, A new perennial species of Gomphrena (Amaranthaceae) from Mexico with nomenclatural notes on G. decumbens, pp. 125-131 in Phytotaxa 722 (2) on page 130, DOI: 10.11646/phytotaxa.722.2.2, http://zenodo.org/record/18598054