Taxonomic value of pollen in Scrophulariaceae sensu lato.

Abstract

Taxonomic value of pollen in Scrophulariaceae sensu lato. This paper is result of a study of pollen morphology of 32 species belonging to 19 genera of Scrophulariaceae sensu lato. A comprehensive record of available information on the pollen morphology in this group in order to analyze the relationships between palynological variables and the current systematic classification was also conducted. Pollen grains are monads, radially symetric and isopolar, the sizes vary from small (11 ?m) to medium (51 ?m), predominately spheroidal (P/E = 1), sometimes suboblates (P/E = 0.76), oblate-spheroidal (P/E = 0.95),
prolates (P/E = 1.63) and perprolates (P/E = 2.63). They are inaperturates, 3- (4-5) colpates, 3- (4-5) colporates, spiraperturates 2-8 syncolpates, 3-colpo-diploporates and pantoporates grains. The exine may be semitectate (retipilate, reticulate or striato-perforate) and tectate (psilate, foveolate, perforate, scabrate, rugulate, verrucate, granulose, striate, echinate). Statistical analysis was performed based on the data matrix of the palynological characters of the 32 species studies in addition to bibliographic references of 140 genera and 218 species belonging to Scrophulariaceae sensu lato. The cluster analysis (UPGMA), confirmed that palynomorphological differences support the current systematic classification.