GALLEGO, P. P. F.; Fabado, J.; Catalan, P.

The taxonomy and nomenclature of the type materials potentially attributable to the three recognized annual species of the grass genus Brachypodium (B. distachyon, B. stacei, B. hybridum) have been investigated through statistical discriminant analysis of twelve quantitative morphological traits in eight herbarium types corresponding to heterotypic synonyms and newly designated types of each species, along with the lectotype and the epitype of B. distachyon and the holotypes of B. stacei and B. hybridum, plus 50 additional representative specimens of the currently recognized taxa, and through a comprehensive nomenclatural review. The possible taxonomic assignments of types to these species and the nomenclatural priority of Brachypodium distachyon and ten related names, B. hybridum, B. macrostachyum, B. megastachyum, B. stacei, Bromus pentastachyos, Festuca monostachyos, F. rigida, Trachynia platystachya, Triticum schimperi, and T. subtile, have been discussed. Lectotypes are designated for Festuca monostachyos, F. rigida, Triticum schimperi, and T. subtile. Based on our taxonomic and nomenclatural study, the names Festuca monostachyos and Triticum subtile can be considered conspecific and heterotypic synonyms of the Linnaean name Bromus distachyos ({equiv} Brachypodium distachyon). Furthermore, the names Brachypodium macrostachyum, Brachypodium megastachyum, Bromus pentastachyos, Festuca rigida, and Brachypodium distachyon var. platystachyon ({equiv} Trachynia platystachya) are conspecific with Brachypodium hybridum, and Triticum schimperi is conspecific with Brachypodium stacei. Since the names B. hybridum and B. stacei are in common use, but both are later heterotypic synonyms, respectively, of the names of the species with which they are conspecific, a proposal for the conservation of these two names is necessary. On the other hand, the application of the names Bromus pauper, Brachypodium geniculatum, Festuca pseudistachya, Bromus paradoxus, and Triticum flabellatum is uncertain, and as such, they are treated as nomen ambiguum. Finally, Festuca ciliata and Triticum asperum are two illegitimate names, according to Art. 52.1 of the Shenzhen Code, while Triticum brevisetum is a new synonym of Brachypodium retusum. A lectotype for the name T. brevisetum is also selected and designated in this paper.