Implication of leaf architecture and its taxonomic significance in delimitation of some selected taxa of the family Malvaceae s. l.

Herein, eleven taxa namely, Abutilon hirtum (Lam.) Sweet, Hibiscus rosa- sinensis L., Hibiscus sabdariffa L., Hibiscus schizopetalus (Mast.) Hook. f., Hibiscus syriacus L., Hibiscus tiliaceus L., Hibiscus trionum L., Malvaviscus arboreus Dill., Sida alba L., Dombeya burgessiae Gerrard ex Harv. and Dombeya tiliacea (Endl.) Planch. were investigated morphologically based on leaf architecture including (leaf blade macromorphological characters, major veins orders, and minor veins orders) for each taxon to estimate the applicability of leaf architectural features in the taxa identification and delimitation. A phenetic relationship between the taxa under investigation based mainly on the major vein categories was constructed using UPGMA and PCA plotting analysis. The resulting clustering dendrogram separated the eleven studied taxa into two main clusters, sharing a set of character states. The first one encompasses five taxa of tribe Hibisceae with a degree of similarity to Malvaviscus arborous that represents tribe Malvavisceae. The second cluster encompasses Sida alba, Abutilon hirtum, Dombeya burgessiae and Dombeya tiliacea, besides Hibiscus tiliaceus. The clustered taxa per each cluster authenticate that there are shared lines between the different taxa not only at triable level but also at sub-familial level. The resulted dendrogram emphasized the taxonomic significance of leaf architectural characteristics in taxa identification, and delimitation at the species level that could be harnessed in solving some taxonomic confusions for species substitutions at tribal level.