Application of anatomy in Plant Systematics & Pharmacognosy

Application of anatomy in Plant Systematics & Pharmacognosy

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  Welcome to Applicationof Anatomy in Systematics & Pharmacognosy (Ppt-2) By N.Sannigrahi, Associate Professor, Department of Botany, Nistarini College, Purulia, 723101(W.B) India The study of the gross internal structure of plant organs by the technique of section cutting is called plant anatomy(ana=asunder; temnein=to cut)”.The qualitative & quantitative information extracted from this domain a significant role in Plant Systematics & Pharmacognosy.
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  Plant Systematics &Pharmacognosy • Plant Systematics-Systematic knowledge about plants for identification, nomenclature & the classification of the plants as par taxonomic rules and regulations as adopted from time to time laid by ICBN • Pharmacognosy-It is the objective study of the crude drugs of animal, vegetable and mineral origin, treated scientifically. Crude drugs are the naturally obtained substances not having been compounded or mixed with the other substances
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  Plant anatomy inSystematics • Anatomical characters of vegetative & floral parts of flowering plants have been successively employed to solve taxonomic problems for the elucidation of phylogenetic relationships. Anatomical evidences can be useful in systematics in several ways • It can be exploited taxonomically in the identification of fragmentary material, say a piece of wood • When morphological characters prove to be of no help in the preliminary identification of herbarium material, anatomical study may helpful.
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  Internal structure ofplants
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  • Anatomical datahas proved to be very useful in discerning evolutionary trends and interrelationships of taxa and above the species level and at higher taxonomic categories. They are most useful in determining relationship between different genera, families ,order & other taxonomic categories. Some of the basic evidentiary anatomical characters of well established taxonomic value used as follows.
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  Vegetative anatomy • Theanatomical data are of broadly two types-Vegetative & Floral anatomy • Vegetative anatomy consists of Leaf ,Stem, Petiole, Nodal & Wood anatomy • Floral anatomy consists of different attributes as offered by the floral parts in course of origin and transformation from vegetative to reproductive parts. • VEGETATIVE ANATOMY • Leaf -----Nature & thickness of epidermis(5 species of Opuntia identified) structure and types of mesophyll, pattern of sclernchyma, silica bodies, chloroplast structure are some of the features considered here.
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  Stem Anatomy • Degreeof elevation of stem ridges • The distribution & abundance of collenchyma • Pattern of collenchyma thickenings • Transformation of ground cells of cortex into transfusion cells- Casuarina • Distribution of Fibers- Genista • Variation in the structure of the cells of the stem of endodermis- Piperaceae, Asteraceae & Lamiacerae • Features of the stem pith- Dubantia & Fitchia • Shape and size of the sclerenchyma girders • Arrangement of vascular bundles
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  Petiole anatomy • Positionof petiole on stem • Presence or absence of stipules • Petiole outline • Numbers of layers of parenchyma in the cortex • Vascularization of the petioles • Distribution of the perivascular fibers • Number of traces—are some of the features used in taxonomy as Metcalfe & Chalk(1950)
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  Wood anatomy • Vesselelement-its length, loss of borders and decrease of bars on perforation • Axial parenchyma-presence or absence, distribution like apotracheal & paratracheal, • Vascular rays • Storied wood, presence or absence of latex vessel, resins, gums, crystals • Sclerides, cellular contents • Unilacunar,trilacular and multilacunar nodes are some of the features used in the taxonomic studies as far as vegetative anatomy is concerned.
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  Floral Anatomy • Reproductiveorgans show high degree of conservation ,have been widely used in plant classification. • The distribution and course of vascular bundles within the receptacle and other features are used in this regard.
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  Flower-a source ofbeauty is more beautiful in anatomical overview
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  Anatomy in Pharmacognosy •Pharmacognosy is the study of the medicines derived from the natural sources. It includes the collection of the different type of plants having therapeutic values, identification, preservation and other attributes. The quantitative & qualitative evaluation of the drugs need the exact sources if it is plants in origin. In course of the study the stomata number, stomatal index I=(S/E+S) *100,Palisade ratio, Vein islet number, Presence of other ergastic substances are considered in this study-both for the identification of plants as well as adulterants.