Pollen morphology of the genus tragopogon (Asteraceae)

Abstract

Tragopogon L. (Cichorioideae, Lactuceae, Scorzonerinae) is an Old World genus with 150 species. Pollen morphology has proved useful in the systematics of some genera and species of Asteraceae as well as in that of some of its genera and species. The pollen morphology of 24 taxa of the genus Tragopogon was investigated in detail by scanning electron microscopy (SEM). The pollen grain type ranged from suboblate, oblate-spheroidal to prolate-spheroidal in equatorial view and hexagonal, obtuse-hexagonal to hexagonal-angular in polar view. In this study separation of the species of the sections Majores, Profundisulcati, Sosnovsky, Chromopappus, Rubriflori according to Flora Iranica is presented from the other species of Tragopogon. T. jezdianus, T. porphyrocephalus, T. rezaiyensis are suggested to belong to Rubriflori section. The results indicate that the palynological characters of the genus Tragopogon are valuable for taxonomic applications and are useful for classification.