Taxonomic significance of cypsela morphology in tribe Cichoreae (Asteraceae) using light microscopy and scanning electron microscopy

Abstract

The current study deals with the detailed morphology investigation of eight Cypsela species belonging to tribe Cichoreae. The different Cypsela types were described, explained, compared, and their taxonomic significance is discussed in detail. Light microscopy (LM) and scanning electron microscopy (SEM) have been used to highlight quantitative and qualitative characters of underestudied species. Cypsela exhibit great diversity in macro and micromorphological features such as shape, color, length, width, anticlinal and periclinal wall patterns, surface patterns, epicuticular projections. Majority of Cypsela species were brownish in color and their size ranges from 2.16 to 3.98 mm in length and 1.16 to 0.82 mm in breadth. A great diversity in Cypsela shapes like oblanceolate to obovate, obovoid to cylindrical, obvate, narrowly lanceolate were observed. Most of the platelets having epicuticular projections were observed. The surface pattern on the cypsela surface varied from rugose papillate, verrucose papillate, and striated. On the basis of considerable variations observed, the present study can assist as useful constraints at various taxonomic levels. The aim of the present study is to provide a comprehensive description of the Cypsela morphology and to determine the extent to which these micro morphological data can be used as a taxonomic character to delineate various taxa belonging to the tribe Cichoreae. © 2019 Wiley Periodicals, Inc.