Stipa orientalis subsp. azutavica, 2016

Nobis, Marcin & Gudkova, Polina D., 2016, Taxonomic notes on feather grasses (Poaceae: Stipa) from eastern Kazakhstan with typification of seven names and one new combination, Phytotaxa 245 (1), pp. 31-42 : 36

12. Stipa orientalis va r. azutavica ( Kotukhov 1998b: 9) M. Nobis & P. Gudkova , comb. et stat. nov.

Basionym: Stipa azutavica Kotukhov (1998b: 9) . Type citation:— Altaj australis, praemontia australi-orientalia jugi Azutau, mons Bulgartabaty, desertum lapidosum, 22 V 1991, Ju. Kotuchov (LE).

Type (original label):— Stipa azutavica Kotuch. sp. nov., Tip: Yuzhnyi Altai, yugo-vost. predgor’ya khr. Azutau, gory Bulgartabaty, kamenistaya pustynya, 22 V 1991, Yu. Kotukhov (lectotype LE! designated here, isolectotypes KRA 436050!, KUZ!, LE!).

Original material (type) of Stipa azutavica preserved in LE consists of nine specimens from a single gathering mounted on two sheets. Two additional sheets with seven original specimens, not mentioned in protologue of this taxon, are preserved in KUZ and KRA. Because the holotype was not indicated by the author, we designate a sheet containing four individuals as the lectotype.

Stipa azutavica is very close to S. orientalis . Kotukhov (1998b) distinguished this taxon from S. orientalis by having somewhat shorter awns (4–5 vs. 5–7 cm long, respectively), ligules of the vegetative shoots covered by longer hairs, and slightly scabrous to almost glabrous leaves.

As a result of revision of Stipa orientalis from its entire range, we found that the ranges of the main characters of this taxon are much wider than presented by Kotukhov (1998b). One example is the length of awn, which varies from 3.9 to 9.0 cm; thus, there is no difference between S. orientalis and S. azutavica in this character. The only differences between these taxa are: leaves slightly scabrous to almost glabrous in S. azutavica vs. leaves more or less distinctly scabrous in S. orientalis ; and hairs on ligules 0.7–1.5(–2) mm long in S. azutavica vs. hairs on ligules up to 1 mm long in S. orientalis . The plants of S. azutavica are generally smaller than those of S. orientalis . For all these reasons, we propose to reduce S. azutavica to the rank of variety within S. orientalis .