The morphological and anatomical aspects of 13 species belonging to genera Kickxia, Scrophularia, and Plantago of Saudi Arabia reveal that the species of Kickxia and Scrophularia are distinct from Plantago major. The most notable morphological differences are the absence of adventitious roots and the presence of acaulescent stem in the species of Kickxia and Scrophularia and the existence of adventitious roots and the absence of acaulescent stem in P. major. The species of Plantago possessed rose-shaped radical leaves, whereas the rest of the species studied had cauline leaves or both. The species of Kickxia and Scrophularia have pentamerous flowers with bilabiate corollas, whereas, P. major has tetramerous flowers with tubular corollas. The separation of P. major from the rest of the studied species is the most obvious result obtained from the dendrogram, and this result is consistent with some traditional taxonomic studies that placed Kickxia in the Scrophulariaceae species while separating P. major into an independent family Plantaginaceae. The anatomical findings revealed that the upper and lower epidermal cells of the leaves were irregular with undulate walls in all analyzed species, except in P. major, where they were polygonal with straight walls. Only P. major had amphianisocytic paracytic stomata, but eight Kickxia species had anomocytic stomata and K. hastata and K. abhaica, and the two Scrophularia species had anisocytic stomata. Therefore, this study suggests the retention of the Kickxia in Scrophulariaceae s.l. and maintaining Plantago in Plantaginaceae s.s. Bangladesh J. Plant Taxon. 29(1): 1-11, 2022 (June)

The seed macro- and micro-morphological characters of 13 species belonging to three genera; Kickxia Dumort, Scrophularia L. and Plantago L., collected from different localities of Saudi Arabia, were studied using a Stereomicroscope and Scanning Electron Microscope for evaluating their taxonomic relationships. Three macro-morphological characters of seeds were shape, size, and color while three diagnostic micromorphological characters were seed coat sculpture, the anticlinal and periclinal wall., The seed shape seems to be specific in Plantago L. (peltate, angled) than the two other genera while the color and seed size show little importance. The Plantago L. has a specific rugose sculpture while the other two genera have either tuberculate or alveolate. So Plantago L. was possessed no affinities to Kickxia Dumor or Scrophularia L.. This observation gives extra support to the earlier taxonomic views that suggested the retention of two genera in the traditional family Scrophulariaceae and maintaining Plantago L. in a separate monogeneric family Plantaginaceae Detailed analysis of seed characters of more species is needed to clarify the systematic relationships between the three genera. A key to the identification of studied species based on seed micro- and macro-morphological characters is provide. Bangladesh J. Plant Taxon. 28(2): 385-393, 2021 (December)