Lectotypification of names associated with Chenopodium hircinum (Chenopodiaceae/Amaranthaceae sensu APG): C. bonariense Ten. and two varieties described by Aellen

The growing interest to the ancient South American pseudocereal crop quinoa, Chenopodium quinoa Willdenow (1798: 1301), not only stimulated research on this species and its wild relatives (see Jellen et al. 2011, FAO & CIRAD 2015, Maughan et al. 2019, and references therein), but also spurred taxonomic and nomenclatural studies of these taxa, including issues of typification and/or conservation of their names (e.g., Lack & Fuentes 2013, Mosyakin & Walter 2018). The closest relatives of Chenopodium quinoa are grouped together with that species in a tetraploid (2n = 36) species complex containing such taxa as C. berlandieri Moquin-Tandon (1840: 23) sensu lato, and C. hircinum Schrader (1833: 2). Despite the growing attention to the crop and its relatives, the infraspecific taxonomy of C. quinoa remains problematic. A critical revision and proper typification of all available valid names published in that economically important group should be made to ensure the correct application of these names. The name C. hircinum was recently lectotypified by Mosyakin & Sokolova (2020), based on the specimen from LE (barcode LE00011694). However, some other names linked with C. quinoa and C. hircinum, in particular C. bonariense Tenore (1833: 13) and two varieties validated under C. hircinum by Aellen (1929), have not been typified yet and are investigated here as part of ongoing studies on the genus.

Lectotypification of the name Chenopodium hircinum, a wild relative of the pseudocereal crop species C. quinoa (Chenopodiaceae)

The name Chenopodium hircinum (Chenopodiaceae) applicable to a South American tetraploid species is lectotypified on a specimen deposited at LE (barcode LE00011694, right-hand specimen) that is associated with H.A. Schrader and his herbarium purchased for LE in 1841. A brief overview of relationships of the pseudocereal crop species C. quinoa withC. hircinum (considered to be a wild crop relative and/or progenitor) is also provided. Since the lectotype of C. hircinum in LE lacks mature fruits/seeds, which are important for morphology-based diagnostics of taxa of Chenopodium (and also of infraspecific taxa described within C. hircinum), designation of an epitype with well-developed fruits/seeds is desirable according to Art. 9.9 of the ICN. However, we argue that an epitype should be proposed later, after achieving a better understanding of the variability of C. hircinum and proper typification of its infraspecific taxa, because hasty epitypifications could be nomenclaturally confusing and disrupting. In our opinion, an epitype specimen for that taxon name should represent a plant corresponding to the lectotype and well characterized molecularly, genetically and morphologically.