Systematic significance of seed morphology in the genus Veronica (Plantaginaceae), with special reference to the Egyptian taxa

Seed morphology of 29 taxa including 9 subgenera belonging to the genus Veronica was compared using scanning electron microscopy to assess their diagnostic value for systematic studies. Subgenus Beccabunga is the largest in this study represented by nine taxa. Seed surface often varies from ridged reticulate or verrucose/granulate reticulate to rugose-reticulate. Seed color and size have limited taxonomic significance as their variation is uninformative. Thereagainst, seed shape and seed coat ornamentation present informative characters that can be used efficiently in distinguishing the studied taxa. Our seed features support the DNA sequence data in showing close relationships between V. biloba and V. campylopoda, and between V. fruticans and V. fruticulosa. The present study indicates that V. anagallis-aquatica, V. anagalloides, V. comosa, and V. catenata have more or less the same seed features; consequently, these four former species are most likely representing a single species as reported by earlier studies. Furthermore, V. polita and V. persica are very similar in terms of seed characteristics. Our results justify placement of V. peregina within subgenus Beccabunga and support the monophyly of the subgenus Veronica.