Comparative anatomy and achene micromorphology assessment of two Cousinia Cass. (Asteraceae) species in view of taxonomy

Abstract

Comparative anatomy and achene micromorphology assessment of two Cousinia Cass. (Asteraceae) 
 species in view of taxonomy
 Deniz ULUKUŞ 1, Osman TUGAY 2
 ORCID: 0000-0002-9627-5492; 0000-0003-3980-7648
 
 1 Department of Biotechnology, Faculty of Sciences, Selçuk University, Konya, Turkey
 2 Department of Pharmaceutical Botany, Faculty of Pharmacy, Selçuk University, Konya, Turkey 
 
 Abstract
 Cousinia is a member of the monophyletic tribe Cardueae, which is traditionally subdivided into four taxonomic groups; however, the rank and boundaries of these taxa are highly controversial. The purpose of this study was to contribute to the genus taxonomy by determining the comparative anatomical and achene micromorphological features of C. aintabensis Boiss. & Hausskn. and C. birecikensis Hub.-Mor. that are morphologically similar to each other. In anatomical studies, stem, leaf, and midrib features were determined. Paraffin embedding, microtome sectioning, and safranin-fast green staining were used for the samples. The obtained sections were photographed, and the leaf, stem, and midrib characters were measured. The importance of anatomical characters between species was determined by applying Independent sample T-test test to quantitative characters. In addition, box plot and heatmap analyses of the studied species were carried out. Our results showed that the stem epidermis, inner sclerenchyma and phloem layer; For leaves; lower and upper epidermis mesophyll thickness, palisade parenchyma; In midrib; number of vascular bundles, collenchyma, and phloem are important characters that can be used in the differentiation of species. SEM microscope was used for achene micromorphological examinations. C. aintabensis achene surface ornamentation is identified as striate-retipylate. It was observed that C. birecikensis had striate and irregular reticulate-faveolate surface ornamentation.
 
 Keywords: Asteraceae, Anatomy, Cousinia, micromorphology, Türkiye