Natural Products and Evidence based Herbal medicines I Department of Natural Products and Alternative Medicine Medicinal Botany Medicinal Botany Part 3. Plant TAXONOMY

Plant Taxonomy and Subkingdom and subclass

The following system of classification is used for the plant kingdom: The Plant Kingdom (PHYTA) is divided into three subkingdoms: PLANT TAXONOMY A- Subkingdom PROTOPHYTA (primitive plants) B- Subkingdom THALLOPHYTA (Non differentiated) C- Subkingdom EMBRYOPHYTA (embryo present)

B- Subkingdom THALLOPHYTA (body is a simple thallus, no embryo, not differentiated into stem, root& leaf and dichotomous branching): ♣ Phylum Chlorophyta. e.g. green algae ♣ Phylum Bacillariophyta e.g. diatoms ♣ Phylum Phaeophyta (brown algae) e.g. Fucus ♣ Phylum Rhodophyta (red algae) e.g. Agar ♣ Phylum Eumycophyta (true fungi) e.g Ergot. A- Subkingdom PROTOPHYTA (primitive organisms) ♣ Phylum Microtatobiotes (viruses, phages and rickettsiae) ♣ Phylum Schizomycophyta (bacteria)

C- Subkingdom EMBRYOPHYTA (embryo present) ♣ Phylum BRYOPHYTA (Non-vascular). ♣ Phylum TRACHEOPHYTA (vascular plants). Class Gymnosperm (conifers) e.g. Ginkgo Class Angiosperm (flowering plants): 1. Subclass Dicotyledons (dicots). 2. Subclass Monocotyledons (monocots). Phylum TRACHEOPHYTA (vascular plants):

Class Angiospermae (flowering plants): The angiosperms (flowering plants) form the highest class of Tracheophyta or vascular plants and are divided into two subclasses: A. Monocotyledoneae. Their plants have following characters: ● The embryo has one cotyledon. ● The leaves are usually parallel –veined. ● The vascular bundles of the stem are closed. A. Monocotyledoneae. B. Dicotyledoneae.

Plants belonging to class angiospermae (flowering plants) of medicinal importance families Monocotyledoneae : Liliaceae and Zingiberaceae Dicotyledoneae :Scruphulariaceae, Rubiaceae, Solanaceae Papaveraceae, Compositae, Umbelliferae, Leguminosae and Apocyanaceae. B. Dicotyledoneae Their plants have the following characters: ● The embryo has two cotyledons. ● The leaves are usually pinnately- veined. ● The vascular bundles are open.

Flowers are the organs of sexual reproduction of higher plants and also generally offer the most exact means of identification. The structure of the flower : A typical Flower is composed of the following floral parts : 1-Calyx (K): formed of green sepals (S), free or united. 2- Corolla (C): formed of colored petals (P), free or united 3-Androecium (A): formed of stamens, free or united united with petals ( epipetalous ). 4- Gynoecium (G) : formed of carpels,each is made of an ovary,style,and stigma.

Placentation: It is the arrangement of ovules inside the ovary, of : 1-Axile in which the ovary is multilocular and the ovules arise on the central placenta produced by the united edges of the ovary walls. 2-Marginal,Basal and Apical.

Symbols representing the floral parts: Floral formula (FF): FF represents its structure in a symbolic way. The placentation is usually referred to below the symbol representing the gynoecium. Floral diagram (FD): FD is another way of representing the structure of the flower. It is an imaginary TS showing the arrangement of parts. At the top of FD, a point is usually drawn to represent the axis of the flower. At the base, the bract is present. Calyx (sepals ) K (s) Corolla (petals ) C (p) Male flower ♂ Female flower ♀ Hermaphrodite ( bisexual ) ♀♂ Actinomorphic ( symmetric ) Ө Zygomorphic (asymmetric ) % Androecium A Gynoecium G Indefinite ∞ United parts ( ) Superior gynoecium G Perigynous G _ Inferior gynoecium G