Medicinal Plant Parts - Morphology (PDF)

Parts of a Medicinal Plant- 11 J. Edmondson-Crater Objectives Students should be able to Identify or discuss : The parts of a medicinal plant The structure of the different parts How the different parts of the plant is classified or categorised Parts of a plant  Leaves Stem...

Parts of a Medicinal Plant- 11 J. Edmondson-Crater Objectives Students should be able to Identify or discuss : The parts of a medicinal plant The structure of the different parts How the different parts of the plant is classified or categorised Parts of a plant  Leaves Stems Flowers Fruits Seeds Bark Wood Roots Entire organism Parts of a Plant Parts of flowers used medicinally (1) Leaf leaf compound leaf leaflets Description Thin, flat Green appendages supporting and conducting strands Minimum percentage of active constituents is specified in leaves Difference between leaf and leaflet Leaf leaflet In the case of leaves buds or branches is Buds or branches are absent in leaflets present Leaflet are arranged in pairs Leaves are arranged spirally and are Leaflet lie in the same plane solitary in nature Leaves lie in different planes Leaflets are symmetrical at the base Eg. Senna, neem, roses Leaves are generally symmetrical at the base e.g. digitalis, Belladonna, Vasaka  Normal characteristics of the leaf are Stems apices of the the arrangement margin : petiole presence/absence of stipules Leaves – characteriz ation Diagnostic structures E.g. stomata Microscopic trichomes Stems (2) Stems : descending axis developed from plumule Consist Nodes, Internodes, Buds giving rise to: Branches, leaves , flowers The stems may be: Aerial, Subaerial, underground Weak herbaceous or woody depending on the presence of Mechanical tissues Types of Stems Weak stems Thin and long , unable to stand erect Classified: Creepers or prostate stems Grow flat on the ground without roots (grasses, gokharu) Types of Stems Classification cont’d Piper betel Climbers Too weak to stand alone Climb on supports Tendrils, hooks, prickles, roots Grapes Types of Stems Classification cont’d Twinners Thin and wiry Coil the support and grow e.g. Ipomoea and Phaseolus  Types of Stems Classification Cont’d Herbaceous or woody stems Normal stems Soft, hard, woody E.g. sunflower, Sugarcane, Ephedra Flowers  Flowers (3) Flowers: Modified shoot – production of seeds Typically Four whorls ( arranged in a definite manner) Built upon a stem or pedicel With enlarge end aka thalamus or receptacle The four whorls: Calyx Corolla Androecium Gynoecium Gynoecium coroll a Androeciu m Caly x The four whorls Calyx Outermost part of the flower Generally green Individual member called Sepal Corolla: Second whorl White or bright colour Each member known as petal Number of metals vary with flower type The four whorls Third whorl - Androecium: Constitutes male part Individual component – stamen Filament, anther, connective Fourth whorl -Gynoecium: female part component known as – carpel /pistil Constitutes -Stigma , style, ovary Drugs studied as Flowers Drugs studied as flowers are either: Entire Flowers in the Botanical sense Inflorescence – complete head of a plant stems, stalks, bracts, and flowers. Single part Stigmas Parts of flowers used medicinally (1) Inflorescence  Raceme -Digitalis, Mustard  Panicle (compound raceme) - gold Mohair  Capitula (head) - chamomile. Arnica, artemisia, Sunflower Parts of flowers used medicinally  Inflorescence Cont’d  umbel Caraway, fennel  Cymose Jasmine  Hypanthodium Fig Parts of flowers used medicinally (2) Stigmas - Saffron (3) Corolla and stamens - Elderflowers Parts of flowers used medicinally (3)Petals -Rose, red Poppy (4)Flower buds -Cloves Fruits Fruits (5) FRUITS Formed: Fertilization > ovules converted (seeds) > ovary walls develop > Protected covering over the seed (Pericarp). Pericarp layers Epicarp ---- thin ,thick , woody Mesocarp---- pulpy/ spongy parenchymatous tissue Endocarp--- thin thick / woody  Unfertilized Ovules: Produces Seedless fruits Category of fruits -- based on number of Carpels Furits Simple Aggregate Compound  Category of fruits: Simple fruits – single carpel /syncarpous gynoecium Mesocarp - dry /fleshy > dry fruits / fleshy Category Fruits of fruits Dry fruits > classified > dehiscent and indehiscent fruits Aggregate fruits: Carpels /apocarpous gynoecium Compound fruits Flowers come together to form fruits. Category of Fruits picture Category of Fruit False fruits / pseudocarp: Parts of a fruit Formed from other floral parts Thalamus Receptacle Calyx Examples of Pseudocarp Strawberry ( Thalamus) Cashew nut (Peduncle and Thalamus) Apple ( Thalamus) Marking nut ( Peduncle) Rose (Thalamus) Pharmaceutical Fruits Pharmaceutical fruits May/may not contain all three layers Examples: Lemon and orange ( only Epicarp) Tamarind and bael ( Mesocarp) Fennel and Dill ( all layers) SEEDS  Seed Fertilized ovule Condensed life ( Phanerograms) Parenchymatous of the ovule Seeds ( nucleus) Embryo sac ( surrounded > integuments) fertilization Takes place > Characterization embryo of seeds: Embryo endosperm (may /may not) seed coat Seeds Classification: (1) Endospermic/ albuminous seeds A part of the endosperm remains until germination Absorbed by embryo Distinct presence of the endosperm Example - Colchicum, Isapgol, linseed, Nux Vomica, Strophanthus Non-Endospermic / Exalbuminous seeds Non-endospermic seeds: During development of seed Endosperm is fully absorbed by embryo not represented by natural seeds Example – Sunflower Tamarind Cotton Soybean Perispermic Seeds Perispermic Seeds: Development of the nucleus > Big storage tissue Seeds contain: embryo , endosperm, perisperm seed coat Example: Pepper Cardamom nutmeg Seeds structures Characterization of seeds structures: a) Hilum : seed to stalk b) Microphyle : minute opening of the tubular structure -provides water for seed germination C) Raphe: longitudinal marking of adherent stalk of anatropous ovule Seeds structures Special structures: Aril Succulent growth from hilum covering the entire seeds ( nutmeg) Arillode Outgrowth originating from the micropyle and covering the seed - Cardamom Arista (awn) Stiff bristle like appendage with many flowering glumes of grasses (Strophanthus) Caruncle Warty outgrowth from the micropyle ( cotton, croton viola) Strophiole Enlarge Funicle (Datura Fastuosa and colchicum seed) Hairs Gossypium and Calotropis Barks  Barks – Definition Obtain Young from Barks Barks: stems and roots Lies Epidermis Via Secondar outside AKA longitudi cortex y the periderm nal and pericyclic external cambium - Three transvers tissues in stem / layers e Phloem root of Cork- incisions Secondary through dicotyled Cork Cambium Cortex the outer onous (Phellem (Phelloderm layer plants ) (Phelloge ) n) Characteristics of Barks Barks Exhibit several morphological and microscopic characters Morphological characters Helps in identification of barks Characteristics of Barks Several morphological and microscopical Shapes in Barks character Identify barks Dependent on preparation Methods Type of incision Extent of shrinkage of tissues Characteristics of Barks Source Method Shape Example Large tree Dried under pressure Flat Arjunia - Quillaia Small Shrinkage of soft tissues Curve shape -wild cherry, branches Concavity (inner cassia side) Recurved - kurchi (outside) Channeled shrinkage Gr. Extent forming deep channeled Cinchona rough channel ledgeriana Cassia Quill One side of bark covers on the Java cinnamon other to form a quill Double quill - Both edge of the bark roll - Cinnamon Compound independently /Recurved Shapes in Barks Shapes Fractures in Wild Cherry Barks Cinchona Fracture of a bark Is the appearance of transversely broken surfaces on the bark. Cinnamon Quillaia Fractures in Barks Types of Surfaces Examples fractures Short Smooth Cinnamon, kurchi Granular Small rounded in appearance Wild cherry, Cassia Splintery Broken ( uneven projecting points) cinnamon Fibrous Numerous fibers on transversely broken Cinchona surface Laminated Arrangement of layer one over the other Quillaia Fractures in Barks Additional Diagnosis Outer and inner surface Colour LICHEN Condition and presence of growth Lichens mosses MOSS Lenticles Developments of cracks Fractures in Barks Inner surface Outer surface Striations – longitudinal and parallel lines Cracks and fissures Lack of elasticity / increase of girth of trees Transverse wrinkles –corrugations Fissures – usually deep Wrinkles – shrinkage of inside soft tissues Furrow – trough between wrinkles Fractures in Barks WRINKLES and CRACKS and FURROWS FISSURES Woods Dicotyledonous plants wood > Tissues produced –cambium (inner side) Consist – mainly xylem + small amount of other tissues Tissues – lignified Two types wood Heart wood Sap wood/ alburnum Wood Heart wood – sandal wood Inner most central region of dicot stem or root non-functioning Non- living Dark coloured ( several chemical substances) Eg tannins pigments gums resins Gives mechanical support Wood Sap Wood Outer region of the wood Functional Conducting food and water Lighter colour Eg. Quassia ROOTS  Underground part of plant Undergroun Roots d Drugs- underground modification of roots stems Rhizomes Tubers Bulb corm subaerial modification of stem Runner Stolon Offset Sucker Underground Drugs Underground modification Rhizome -Grow horizontally under the soil - Ginger, turmeric, -Thick, fleshy - characterized – nodes, internodes, scale leaves rhubarb, Dioscorea, male -Possess bud in scale leaf axil fern - Adventitious roots ( may be present on lower surface of Rhizomes) - Serve as storage organs Tuber - Characterized –presence of eyes ( vegetable buds) grow & - Potato, Jalap, aconite, develop into new plants Dioscorea - Swollen underground structures of plants - Organs of storage and propagation Rhizomes and tubers Examples Rhizomes TUBERS Underground Drugs Underground modification Bulb - Specialized underground shoots Garlic, onion, squill, - Food material stored in fleshly scales (overlap gloriosa stems) Corm - Stout grows in vertical direction Saffron colchicum - Bears bud in axil of scale leaf - Buds forms new plants - In base of corm > adventitious roots - Growth of corm is sympodial Blubs and Corm Examples Underground Subaerial modification of stems Runner -Their specialty creepers on the ground - Strawberries -roots at nodes. - Pennyworth - Auxiliary buds present Stolon -lateral branches arising from base of stems - Glycyrrhiza, - Characterized by Presence of nodes and internodes - Jasmine , arrow root - Branches growing above the ground develop into new plants Runners and Stolon Example strawberry roots Underground Subaerial modification of stems Offset - Originate from the axil of the leaves (short thick - Aloe horizontal branches) - Valerian, Agave - Present as rosette type leaves - Cluster roots - Shorter and stouter than runners Sucker - Lateral branches developed from underground stems Banana, Mentha - Grow obliquely upwards giving rise to a shoot ( new species, pineapple plant) - Characterized by scale leaves Suckers and Offsets Example Aloe Banana suckers Roots Characterized by Downward growth in soils Branching roots arise from pericyclic tissues Covered by root caps / root heads No clear demarcation between roots and rhizomes Both contain a great proportion of each Utilization of Medicinal Plants by parts Plant Part Percentage 1. Roots 29% 2. Whole Plant 16% 3. Barks 14% 4. Fruits 10% 5. Seeds 07% 6. Leaves 06% 7. Stems 06% 8. Flowers 05% 9. Rhizomes 04% 10.Wood 03% Entire Organism - Drug Denotes major proportion of a plant Aka Herbs ( all aerial parts ) ( not main axis of stem) Leaves flowers seeds smaller stems Eg. Belladonna, Cannabis, Datura, lobelia Entire organisms Ergot – dried sclreotium of fungus Ephedra- constitutes the stem portion of the plant Organized and unorganized crude drug Organized (cellular) Crude drug Dried parts of plants / animals Cellular structure Organs – leaves stems flowers Unorganized (acellular) Crude drugs Parts of plant/animals Obtained by extraction process Examples – oils, juices, lotions Differences between organized and unorganized crude drugs Organized crude drug Unorganized crude drug 1. Organs of plants and animals 1. Derived from plants and animals by - Made up of cells /definite process of extraction structures - Followed by purification - Name flowers, seeds, fruits, - Juices, extracts, resins insects….. 2. These are solid in nature 2. Solids , semi-solids /liquids - Oils, gums, balsams Differences between organized and unorganized crude drugs Organized crude drug Unorganized crude drug 3. Botanical / Zoological terminology 3. Such terminology are inadequate for can be used to describe these drugs description - Use of their physical characteristics where applicable ( solubility, density, optical rotation, refractive index 4.Important character of identification 4. Chemical tests Physical standards is Microscopic - eg. Digitalis, ( confirmatory) cinchona, clove, fennel, jalap, Aloe, agar, colophony, opium, cochineal castor oil, bees wax pepsin Description of some unorganized drugs- physical description Gums 1. Translucent and amorphous 8. Aqueous solutions of gum are usually substances laevorotatory 2. Pathological products ( grow unfavourable conditions / injured) 9. Plant hydrocolloids – anionic / nonionic polysaccharides 3. Abnormal products of plant metabolism 10. Hydrolysis / prolonged boiling (water) – yields sugar & uronic acids 4. Produce by “Gummosis” (glucoronic ,galacturonic & aldobionic acids) 5. Soluble of partly soluble in water 11. Forms salts with calcium and Magnesium 6. Insoluble in alcohol and most organic 12. Pharmaceutically important gums – solvents acacia, tragacanth, karaya, ghatti, guar. 7. Forms viscous adhesive solutions ( via swelling due to absorption) Description of some unorganized drugs- physical description Mucilage 1. Similar to gums 5. Examples + method of formation of mucilage's from 2. Normal products of plant metabolism ( produced inside the cell) a) Cell wall of seed epidermis –Isabgol, linseed 3. Forms slimly masses but do not dissolve b) Endodermis - Fenugreek 4. Esters of sulphuric acids- ester group is a polysaccharide complex c) Leaf epidermis – Senna d) Bark – Cinnamon, Slipper-elm e) Special secretion cells - Squill f) Algae – Agar , chondrus Resins and Resins combinations Types of Resins Synthetic  Natural Resins - Obtain from plant and animal sources - Animal source – shellac / lac Plant resins: Natural / induce exudates Solid liquids semi- viscous materials Resins and Resins combinations Plant resins cont’d: End products of plant metabolism Clear, translucent, yellow /brown Soluble in most organic solvents ( alcohol, chloroform, carbon disulphide, benzene Insoluble in water Heated > soften> burns with soft flame Darken on storages ( chemical changes) Resins and Resins combinations Plant resins cont’d Chemically, natural resins organic compounds (no nitrogen) Groups Various groups – acids alcohols esters neutral substances Podophyllum resin, jalap resins, colophony, sandarac, guaiacum Resins and Resins combinations B) Oleo- resins Natural plant resin + volatile oils ( homogeneous) Example – Canada Balsam Copaiba C) Balsams: Aromatic resinous substance + balsamic acid (i.e. benzoic and cinnamic acids) Example – tolu benzoin storax balsam of Peru Canada balsams / balsams of Copaiba ( no balsamic acid) Not real balsam  D) oleo- gum Resins: Combinations of volatile oils , gums , resins sometimes contain Enzymes eg. Myrrh asafoetida Location of Resins in different parts of plant Location of Resins Different parts of plants and animals a) External glands : Indian Hemp (cannabis) b) In the heart wood of some woods: Guaiacum and red sanders c) Internal glands of plants: male fern d) Glands on surface of insects: Shellac Location of Resins in different parts of plant Resins from internal cavities Unicellular – (ginger, capsicum, jalap) Multicellular – (clove) Cavities Schizogenous / schizolysigenous (origin) Normal physiological products Pathological products (injury) Resins and Resins combinations iii) Dried juices Obtained - fleshly leaves / stems ( aloe kino) Incisions are made to parts > juices are collected and dried iv) Latices Latex product ( special secretory tissues) Aqueous white suspension ( micro. Small particles of oil particles suspended) Milky consistency – proteins sugars mineral alkaloids salt (in true solution) Resins and Resins combinations iv) Latices cont’d Gums starch resins (suspended forms) Examples commercial latices Rubber chicle gum Pharmaceutically latices – opium papain ficin gutta percha Distribution of medicinal plants Plant type Coverage Trees 33% Herbs 32% Shrubs 20% Climbers 12% others 03% v) Extracts Crude drugs Different from galencial extracts Pharmacognostic extracts Extracting parts of parts with water > concentration Prepare pharmaceutical preparation Using alcohol / hydro-alcoholic solutions Adjust to standard strength Ex ample : agar | sodium alginate| catechu | gelatin (animal source) References https://www.bing.com/images/search?q=Banana+Rhizome&form=RESTAB&first=1 https://www.bing.com/images/search?q=aloe%20roots&qs=MM&form=QBIR&sp=1&pq =aloe%2Froots&sc=8-10&cvid=E8B9129AFA614FD5BF2DA94D6BAE02DE&first=1&sce nario=ImageBasicHover https://www.bing.com/images/search?q=offset+Root+Runners&qs=n&form=QBIDMH& sp=-1&pq=offset+root+runners&sc=0-19&cvid=FB17BD2508F14F49892143223CAE5E 16&first=1&scenario=ImageHoverTitle C.K. Kokate, A.P. Purohit, S.B. Gokhale Pharmacognosy.