Identification of a different ultrastructure type in Tulipa julia K. Koch

A palynological study of the Tulipa genus reveals distinct ultrastructural characters in Tulipa julia compared to the other examined species. Pollen micromorphology and ultrastructure of this species are determined by using Light Microscopy (LM), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). Pollen grains are monads, medium, and oblate-spheroidal. The exine ornamentation is rugulate-tuberculate. Also, ultrastructural observations show the presence of the endexine layer, the foot layer relatively thinner than the tectum, and a similar thickness between the ectexine and intine layers. Although, some pollen micromorphology characters align with the previous palynological research, the unique ultrastructural features such as the tectum/foot layer ratio (T/F) and presence of the endexine layer are determined in T. julia. These sporoderm data can be valuable for taxonomic classification at the subgenus Tulipa (T/F ratio and the number of intine layers) and section Tulipanum (presence of the endexine) levels.