tailieunhanh - Achene morphology of the genus Cota J.Gay (Asteraceae) from Turkey and its taxonomic significance

They show variation in color: brown, dark brown, grayish-brown, reddish-brown, purplish-brown, black, and purplish. All investigated species have slime cells, but prismatic cells on epicarpic cells are found only in two species. | Turkish Journal of Botany Turk J Bot (2018) 42: 208-223 © TÜBİTAK doi: Research Article Achene morphology of the genus Cota (Asteraceae) from Turkey and its taxonomic significance 1 1, 2 Mehmet Ufuk ÖZBEK , Funda ÖZBEK *, Mecit VURAL Department of Biology, Faculty of Science, Gazi University, Ankara, Turkey 2 Nakış Street 37/5, Dikmen, Ankara, Turkey 1 Received: Accepted/Published Online: Final Version: Abstract: Twenty-two taxa of the genus Cota (Asteraceae) from Turkey were examined with a stereomicroscope and scanning electron microscope (SEM) in order to describe their achene macro- and micromorphologies and to evaluate the diagnostic value of these features. The achenes are obpyramidal, obconical, and oblong. Achene width ranges from to mm and achene length from to mm. They show variation in color: brown, dark brown, grayish-brown, reddish-brown, purplish-brown, black, and purplish. All investigated species have slime cells, but prismatic cells on epicarpic cells are found only in two species. Four types of ornamentations were recognized via SEM on achene surface characteristics: reticulate-striate-ruminate, reticulate-striate, reticulateruminate, and reticulate-rugose. Achene size, surface ornamentation, and color are of significant importance in taxonomy of the genus for distinguishing taxa from each other. Key words: Compositae, Cota, fruit, macro-/micromorphology, systematics 1. Introduction The genus Cota (Asteraceae, Anthemideae) consists of 49 species (including 63 taxa) worldwide. Cota species are mainly distributed in Europe (except north of Europe), North Africa, Caucasia, and Central Asia (Davis and Hedge, 1975; Oberprieler et al., 2007). In Turkey it is represented by 15 species and 22 taxa, of which 9 are endemic. The members of Cota are especially widespread in the Mediterranean and Irano-Turanian .