Taxonomic identification in the tribe Cynoglosseae (Boraginaceae) using palynological characteristics

Abstract

The palynomorphological characteristics of 31 species belonging to 8 genera (Paracaryum, Mattiastrum, Microparacaryum, Rindera, Cynoglossum, Solenanthus, Trachelanthus and Lindelofia) of the tribe Cynoglosseae (Boraginaceae) were studied in detail. Palynological observation of the tribe revealed that shape of pollen grains was frequently prolate, subprolate, prolate spheroidal and preprolate. The similarity in some features of the pollen shape and apertural type has been found in several genera such as Cynoglossum, Trachelanthus and Lindelofia. The main ornamentation type was psilate-punctate, psilate-perforate, microgranulate, punctate-microreticulate, scabrate, reticulate, microechinate, punctate-perforate. The species were classified into two pollen types: (i) Rindera tetraspis type and (ii) Cynoglossum officinale type on the basis of aperture characters and surface ornamentation. In present research both genera and species were delimited in the tribe Cynoglosseae. Main objective of the present research is to study different palynological characters for the identification and species delimitation in the tribe Cynoglosseae (Borginaceae). The present findings of the palynological characters are of great interest for the taxonomists for the accurate identification of genera and species in tribe Cynoglosseae. The micro-morphological characteristics of pollen show many novel features for the correct taxonomic identification and species delimitations and this study provide many valuable information to plant taxonomists for further studies.