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In 1849, Ernest Saint-Charles Cosson published, on the page 69 of "Notes sur quelques plantes de France critiques, rares ou nouvelles, fasc. II", a new taxon collected from Iberia (Buxbaum, J.C. loc. cit., near Caucasia, in modern Georgia) and Tauria (Tausch, I.F. loc. cit.). He designated it as Ae. tauschii Cosson, in memory of an outstanding botanist, Ignas Friedrich Tausch. This taxon is actually the one which is now known as the D-genome diploid Triticeae species. These specimens were confused with Ae. squarrosa L. by J.C.D. von Schreber (1769) and I.F. Tausch (1837). It was confused with Ae. caudata L. by James Edward Smith and John Sibthorp in 1806 (see Flora Graeca I, page 76). That specimen from Tauria was confused and designated as Ae. cylindrica Host var. taurica by Johann Jakob Roemer, and Jos. Augusto Schultes in 1817 (see Caroli a Linne Systema vegetabilium secundum classes, ordines, genera, species, cum characteribus, differtiis et synonymiis, II, page 771 ).

In 1812, Ambrois Marie Francois Joseph Palisot de Beauvois combined Ae. squarrosa L. to the genus Triticum and gave it a new species name, aegilops. In 1896 he mix-identified the D-genome diploid taxon as Ae. squarrosa L.. He reported and named it as Triticum aegilops P. Beauv. in Flora of British India, vol. VII, (which was edited by J.D. Hooker. and O. Stapf in 1896). He explained that his description was based on Ae. squarrosa L. Because of his big name, de Beauvois' mis-identificatiion had a strong influence on many people, including some experts, such as P.M. Zhukovsky (1928) and A. Eig (1929), who followed de Beauvois and made the same mistake by using the invalid name Ae. squarrosa L. for the taxon of the D-genome diploid species.

On page 654 of his book "The Grasses of Burma, Ceylon, India and Pakistan", N.L. Bor (1960) reported :"A recent examination of the type of Ae. squarrosa in Linnean Herbarium shows that it is a form of Ae. triuncialis Linn., hence the species called Triticum aegilops P. Besuv. in the Flora of British India, based on Ae. squaresa Linn., must be known by the next available name--Aegilops tauschii Cosson". The authors proved this by a high quality photograph of the type specimen which was stored in Copenhagen, Denmark. Therefore, Zeven and Zhukovsky (1975) called the D-genome diploid species Ae. squarrosa auct. non L. However, this designation, too, is not valid according to International code of botanical nomenclature (Greuter et al. 1994).

Hackel (1887) combined genera Aegilops L. and Triticum L. into one genus Triticum L. Following the suit, Aegilops tauschii Cosson was included in genus Triticum ten years later and changed the name to Triticum tauschii (Cosson) Schmalh. (see Schmalhausen, Ivan Fedorovich (1827). F1. Centr. et S. Russia, 2, page 662).


Discussion

Of the two species epithet names, squarrosa and tauschii, which one is legitimate? This is the question often being asked. A legitimate name has to follow the International Code of Botanic Nomenclature. According to the Code, "the application of names of taxonomic group is determined by means of nomenclature types" (Principle II); "the nomenclature of a taxonomic group is based upon priority of publication" (Principle III); and "each taxonomic group with a particular circumscription, position, and rank can bear only one correct name, the earliest that is in accordance with the Rules, except in specified cases" (Principle IV). Obviously, the legitimate name of the Dgenome diploid Triticeae species has to meet these two criteria: priority and correctness. Of the two popular species names for the D-genome diploid, squarrosa was published earlier than tauschii, and that is why many researchers regard it the right name. However, Linne (1753, 1763) did not assign the name "squarrosa" to the D-genome diploid species but to a form of the tetraploid triuncialis. It was a misidentification made by de Beauvois (1896) that led to the popular usage of the "squarrosa" to call the D-genome diploid. Cosson (1849) was the first to assign the name "tauschii" to the D-genome diploid, based on nomenclature types from Iberia and Tauria. Hence the name tauschii has the priority, and, because it follows the Code, it is correct. Obviously, "tauschii" is the sole legitimate name of the D-genome diploid species, regardless which genus, Aegilops or Triticum, it belongs to.

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