Morphological and Anatomical Studies of Vascular Variant for Some Dicotyledon and Monocotyledon Stems in Egypt

Vascular variants are deviation from normal vascular systems for some different stems of plants especially angiosperms, where found in some trees, shrubs and herbs. The investigation will trace the different forms of vascular variants of some dicot and monocot herbaceous and shrubby plants in Egypt as Amaranthus viridis L., Chenopodium murale L. (Amaranthaceae), Luffa cylindrica M.Roem. (Cucurbitaceae), Bougainvillea spectabilis willd. (Nyctaginaceae), Nerium oleander L. (Apocynaceae)} and three monocotyledonous species {Cordyline fruticosa L., Chlorophytum comosum Thunb. and Dracaena marginata Lam. belonging to (Asparagaceae)}. According to the anatomical study, there were different reasons for vascular variants represented in successive cambium, medullary bundles, intraxylary & interxylary phloem and bicollateral bundles, in addition to secondary thickening meristem through the dicotyledonous and monocotyledon stems respectively. Through the study it turns out that the herbaceous plants Amaranthus and Chlorophytum at the level of dicots or monocots may be considered the most developed based on the evolutionary criteria. By using an unweight pair-group method with arithmetic (UPGMA) dendrogram, three clusters were produced on a similarity scale resulted from all morphological and anatomical data.Throught the study Amaranthus viridis L., Luffa cylindrica M.Roem and Chlorophytum comosum Thunb. may be more developmental plants because they have more than one developed characteristic. Also, Bougainvillea spectabilis willd may be a transitional stage between dicotyledonous and monocotyledonous plants studied. All these conclusions need to be supported by additional evidence.