9. Cyanus matthiolifolius (Boiss.) Wagenitz & Greuter in Greuter (2003: 57).

Centaurea matthiolifolia Boissier (1844: 19) . Centaurea axillaris var. matthiolifolia (Boiss.) Boissier (1875: 637) . Centaurea variegata subf. matthiolifolia (Boiss.) Gugler (1908: 111) . Centaurea cana subsp. matthiolifolia (Boiss.) Sosnovsky (1926: 91) . Centaurea triumfettii var. matthiolifolia (Boiss.) Dostál (1931: 63) . Type:— TURKEY. Caria, 1843, C. Pinard s.n. (holotype G-BOIS! (G00759515: three sheets comprising one specimen), isotypes G00223025!, G00414389!, G00414390!: two sheets comprising one specimen, G-DC! (G00223026: two sheets comprising one specimen)!, GOET008605!, H1086506!, K000794256!, P00703886!, P00703887!, P00703888!, P00703890!, WAG0004179!).

Centaurea cana var. sultanensis Bornmüller (1944: 375), syn. nova.

Type:— TURKEY. Phrygia: ad radices montis Sultandagh, saxosis prope Akscheher (Wilajet Konia), 1000–1100 m, 12 June 1899, Bornmüller 4700 (holotype B 10 0367383!) .

Cyanus akcadaghensis (Uysal & Şirin) Raab-Straube & Greuter in Raab-Straube & Raus (2021: 145), syn. nova.

Centaurea akcadaghensis Uysal & Şirin (2020: 174) . Type:— TURKEY. Malatya: Akçadağ, Levent Canyon, Çayözü Village, open Quercus forest, 1171 m, 28 April 2018, Uysal 3612 (holotype KNYA!, isotype ANK).

Taxonomic notes: — Bornmüller (1944) described var. sultanensis based on his collection from Turkey that is deposited at B. The diagnostic character of this variety is pale-coloured cilia of the appendages. My examination of the herbarium material of C. matthiolifolius deposited at B, E, G, GOET, H, K and WAG confirms the presence of cilia with palecoloured appendages, so this variety is reduced to a synonym of C. matthiolifolius .

Centaurea akcadaghensis Uysal & Şirin was described based on the gathering ‘ Uysal 3612 ’ from Akçadağ, Malatya Province, Turkey (Şirin et al. 2020). Recently, this name was changed to Cyanus akcadaghensis by Raab-Straube & Greuter in Raab-Straube & Raus (2021). According to Şirin et al. (2020), C. akcadaghensis differs from C. matthiolifolius by its stem, leaves, central florets, and achenes as following: stem simple and ascending (vs. simple and erect), basal leaves lanceolate, 3.6–4.1 × 0.2–0.9 cm (vs. linear-lanceolate, 2.9–8.5 × 0.6–1.2 cm), cauline leaves lanceolate, 1.5–3.7 × 0.3–0.5 cm (vs. linear-lanceolate 2.6–4 × 0.2–0.6 cm), central florets purple, 10–13 mm long (vs. purple, 13–15 mm long), and achenes ovoid-oblong, 3.1–3.6 × 1.4–1.9 mm (vs. ovoid-oblong, 4–4.5(–5.5) × 2–2.5 mm). A detailed comparison on the descriptions of this new species and C. matthiolifolius showed a high level of similarity between them. Şirin et al. (2020) stated that C. akcadaghensis have a simple and ascending stem, while the stem in C. matthiolifolius is simple and erect. After examining other relevant specimens, I found that C. matthiolifolius also has ascending stems. Moreover, size and shape of leaves, color and length of central florets and shape of achenes overlap in C. akcadaghensis and C. matthiolifolius . There is only a minor difference: achene size was 3.1–3.6 × 1.4– 1.9 mm in C. akcadaghensis versus 4–4.5(–5.5) × 2–2.5 mm in C. matthiolifolius, which is not reliable in Centaurea s.l. Therefore, I concluded that C. akcadaghensis should be merged with C. matthiolifolius .

Distribution: — Cyanus matthiolifolius is endemic to Denizli, Burdur and Isparta Provinces, SW Turkey (Fig. 5).

Selected specimens examined:— TURKEY. C2 Denizli: Honaz Da., 1700 m, Huber-Morath 5416 (Hb. Hub. - Mor.!); 27 km sudlich Denizli auf dem Kazik beli, 2 July 1973, Holtz et al. 00.469 (E!) . Burdur: 15 km from Tefenni to Yeşilova, 1100 m, 1 June 1962, Dudley 35290 (E!) .