2. Stipa argillosa Kotukhov (1998a: 8). Type citation:— Altaj australis, praemontium jugi Azutau, locus Bulgartabaty, desertum praemontanum, denudatio argillarum tertiarium, in argilloso-schistosis, 22.V.1991, Ju. Kotuchov (LE)

Type (original label):—Severnoe Prizaisan’e, yugo-vostochnye peredgor’ya khr. Azutau, urochishche Bulgartabaty, peredgornaya pustynya, obnazheniya tretichnykh glin, glinisto-shchebnistye uchastki, 22 V 1991, Yu. A. Kotukhov (lectotype KUZ! designated here, isolectotypes KRA 436051!, KRA 436052!, KUZ! 4 sheets).

We did not locate the type of this species at LE, so we are proposing a lectotype. The lectotype was selected from Kotukhov’s original collection of the species preserved in KUZ.

Stipa argillosa is close to S. sczerbakovii. The most conspicuous character distinguishing these two taxa is the length of ligules of vegetative leaves (up to 0.2 mm long in S. argillosa vs. 0.3–2.7 mm long in S. sczerbakovii). They do not differ by the length of hairs on the upper segment of the awns and the length of anthecium as noted by Kotukhov (1998a). Stipa argillosa is also close to S. lessingiana, but differs by having much shorter hairs on awn seta (0.9–1.3 vs. 1.8–3.5 mm long, respectively).