Systematic implications of fruits and seeds of Plantaginaceae and some related genera of Scrophulariaceae

Abstract

Fruit and seed macro-and micromorphological analyses were carried out of 18 Plantago species representing two subgenera (Euplantago and Psyllium), and 18 taxa representing nine genera related to Scrophulariaceae sensu lato (s.l.) were investigated by light microscopy (LM) and scanning electron microscopy (SEM). The main aim of this study was by studying the fruit and seed morphological characters to investigate the phenetic relationships among Plantago species, as well as between certain taxa of Plantaginaceae sensu lato (s.l.) formerly assigned to the family Scrophulariaceae. The phenetic analysis of fruit and seed morphological characters of all studied taxa produced a phenogram that showed two main series: the first comprising the Plantago species [Plantaginaceae sensu sricto (s.str.)] and the second including the studied Scrophulariaceae taxa. The resulting phenogram supported the retaining of the studied Scrophulariaceae taxa within the family Scrophulariaceae s.l. and Plantago in a distinct monogeneric family Plantaginaceae s.str., and was incompatible with the new circumscription of Planataginaceae s.l. Moreover, the present findings were in line to a certain extent with Shipunov's infrageneric classification of Plantago.