Taxonomic importance of nutlets and flowers in tribe Cynoglosseae (Boraginaceae)

The macro and micro-morphology of flowers and nutlets of ۳۵ species of Boraginaceae belonging to the Tribe Cynoglosseae have been studied by light and scanning electron microscopes. These include Paracaryum (۸ species), Mattiastrum (۱۱ species), Microparacaryum (۴ species), Rindera (۴ species), Cynoglossum (۳ species), Solenanthus (۲ species), Trachelanthus (۱ species), and Lindelofia (۱ species). Nutlets morphology of the examined species showed significant variation in shape, size, and surface ornamentation. Two main types of nutlets were defined: Type I, without a wing, nutlets densely glochidiate, was observed in Cynoglossum, Solenanthus, Trachelanthus, and Lindelofia; Type II, characterized by winged nutlets, was found in all examined species of Paracaryum, Mattiastrum, Microparacaryum, and Rindera. Our results highlight the importance of the floral and nutlet characters for the identification of the most studied species, based on cluster analysis. The main aim of the present study is to investigate the macro and micro-morphological characteristics of the studied species for the taxonomic identification and species delimitation at the tribal level. For quick and easy identification of the species, identification keys based on floral characters have been developed.

کلیدواژه ها:

Floral structure ، fruit morphology ، Micro-morphology ، PCA analysis ، Boraginaceae ، Cynoglosseae ، Iran