Usama K. Abdel-Hameed

Diversity and evolutionary trends in the floral characters of some taxa of Scrophulariaceae sensu lato

ABSTRACT The diversity of the floral characters in 17 species of Scrophulariaceae Juss. (belonging to 12 genera) was carried out through the tracing of their states as pictured by the organ vascularization. According to the statement of evolution (floral criteria) the character states were given evolutionary grades and the latter were “clipped” to their corresponding taxa. Trends of evolution in the floral characters were found to be gamosepaly, sympetaly, bilateral symmetry, reduction trends in the number of stamens as well as their vascularization and the occasional presence of a placental vascular cord as a fusion product of the carpellary ventral traces. None of the taxa under investigation could be considered as advanced over the other since all retained mosaic evolution expressed by variation in the vascular pattern in sepals, petals, stamens and carpels. In addition the obtained data confirmed that the line of evolution inside tribe Antirrhineae is from Antirrhinum majus L. (representing less advanced case) to Kickxia aegyptiaca (L.) Nábělek (the most advanced studied species). Russelia equisetiformis Schlecht. & Cham. occupied the lowest position vs Scrophularia xanthoglossa Boiss. (tribe Cheloneae). The ventral cord and lateral carpellary bundles pattern supported the taxonomic location of Paulownia tomentosa (Thunb.) and Torenia fournieri Linden ex E. Fourn. under family Scrophulariaceae.