Aegilops caudata was diagnosed by Linnaeus as "Spica subulata scabra, flosculo ultimo tantum aristato". In addition, Linnaeus cited the phrase name from Tourefort (Inst. Rei Herb., Coroll.: 29. 1703), "Gramen creticum, spica gracili in duas aristas longissimas & asperas abeunte", and added the remark "Habitat in Creta. Glumae omnes, excepta ultima, bidentata sunt". In terms of morphology and origin the species was thereby clearly described and fully recognized as such in the two monographs of the genus Aegilops (Zukovskij in Trudy Prikl. Bot. 18: 417-609. 1928; Eig in Repert. Spec. Nov. Regni Veg., Beih. 55: 1-228. 1929). The only confusion that could possibly arise was with A. cylindrica Host (Icon. Descr. Gram. Austriac. 2: 6, t. 7. 1802), a tetraploid species which also occurs, but rarely, on Crete (Slageren, in prep.). Differences are: (1) the length and development of the apical glume awns: equal or (usually) longer than the entire spike and with a base which is a continuation of the apex of the glume (in A. caudata) vs. only about one-third to one-half of the spike length (in A. cylindrica); (2) the absence of small lateral teeth at the base of the apical glume awn (in A. caudata) vs. their presence (in A. cylindrica); and (3) features of the apical lemma awns, which are short and narrowly linear with one or two lateral teeth at the base (in A. caudata) vs. well developed, at least equal in length but usually longer than the apical glume awns (in A. cylindrica). The presence of a well developed awn on the lateral glumes in some forms of A. caudata superficially makes this species look similar to A. cylindrica. The situation changed with the remark by Eig (in Repert. Spec. Nov. Regni Veg., Beih. 55: 13. 1929) that the plants on the two sheets annotated by Linnaeus in his herbarium as "caudata" (Herb. Linnaeus No. 1218.5 and 1218.6, LINN) do not belong to this species. Bowden (in Canad. J. Bot. 37: 667-668. 1959) confirmed this statement for two of the three plants involved [the right-hand plant of No. 1218.5 and the single plant of No. 1218.6, which he identified as Aegilops tauschii Coss. (A. squarrosa auct.)]. The left-hand individual of No. 1218.5 he left with A. caudata as traditionally understood and indirectly accepted it as the type of the name. When treating A. caudata under Triticum, as the combination T. caudatum Pers. 1805 [= Dasypyrum villosum (L.) Cand.] predates T. caudatum (L.) Gren. & Godr. (based on A. caudata L.), he used the epithet of A. caudata subsp. dichasians Zhuk. (in Trudy Prikl. Bot. 18: 512. 1928) to create T. dichasians "(Zhuk.)" Bowden. We agree with Greuter (pers. comm.) that the basionym of this combination, A. caudata