Leaf Anatomy PDF

16/11/2024  - At first all cells are meristematic and after leaves formation, the meristemic cell loses its activity and divides no more...

16/11/2024  - At first all cells are meristematic and after leaves formation, the meristemic cell loses its activity and divides no more - The further growth of the leaf is due to the increase in the size of the cells and to maturation of mesophyll and vascular tissue but not to formation of new cells Structure of the Leaf 2- Petiole or leaf-stalk - The complete leaf is - It is the leaf stalk that connects the blade (lamina) to the composed of three parts twig. - It serves to carry the lamina away from the stem to 1- Leaf base place it in suitable place to the light and to conducts materials to and from 2- Petiole or leaf-stalk the lamina. 3- Lamina or leaf-blade  16/11/2024 3- Compound leaf - The leaves are described according to the petiole to -When leaves are completely segmented into a number of separate leaflets A- Petiolated - Have a petiole attaches to the blade inside from the blade margin. B- Sessile - Do not have a petiole; the blade (lamina) attaches directly to the stem. Structure of the lamina - A leaf typically consists of the following tissues 1- Epidermis -Covers the upper and lower surfaces -,having hairs and stomata 2- Mesophyll T. S. in lamina region  16/11/2024 1- Epidermis Trichomes (Hairs) - The epidermis is the outer layer of cells covering the leaf - Extension to the outside of the epidermal cells which my. It is a protective layer, formed of a single layer or some times of two or more layers with no intercellular spaces, except where be very short and conical (papillae) or long and the pores of stomata protruding (trichomes). Function of Hair - The layer is usually transparent (cells lack chloroplasts) and coated on the outer surface with a waxy cuticle that 1. Protection for the leaf against microbial organisms and prevents water loss. insects. 2. Its secretion used in perfumes, food and pharmaceutical In rare cases, epidermal cells may show contents, e.g. industry. calcium oxalate, diosmin in Buchu, mucilage, etc. - The trichomes are either non-glandular (covering) or glandular with a stalk and swollen head formed of one or - They appear in surface view polygonal more secreting cells. The secretion usually Volatile oil or oleo-resin  16/11/2024 I- Covering trichomes (non-glandular hairs) 1- Unicellular hairs 2- Multicellular: formed of more than one cells a) Branched --------- Cruciferae It is unbranched or branched b) Unbranched------- Senna a- Unbranched or Simple 1) Uniseriate: one row of cells 2) Biseriate: two rows each row of one or more cells 3) Multiseriate: many rows of cells  16/11/2024 b- Branched: II- Glandular hairs 1) Simple-branched: uniseriate body ending in tow branches…Tobaacco 2) Stellate: radiating unicellular hairs… Boldo 3) Peltate: very short stalk surrounded by plate-like structure formed of very close or laterally joined cells. - Cascarilla 4) Candelabra: branched tree-like with unicellular axis from a- Uniseriate stalk: which arise numerous unicellular branches of hairs, several b- Biseriate stalk: being at each point.. Lavender & Rosmary c- Multiseriate stalk: d- Branched stalk: b- Biseriate stalk: and biseriate head as compositae a- Uniseriate stalk: c- Multiseriate stalk: and a head with one or more a) Unicellular head ------ Digitalis or Mentha secreting cells b) Multicellular head ------ two (Digitalis) or more (Datura) d- Branched stalk: the branches ending in 1-celled heads as in Hyoscyamus muticus  16/11/2024 Stomata Each stoma consists of two similar cells called guard Osteole cells (smaller than epidermal cells containing chloroplast and usually starch granules), parallel to one another and enclosing between them a small lenticular or oval space called osteole. The cell surrounding the stomata are different from the Guard cell remaining epidermal cells and called subsidiary cells Types of stomata 2. Anomocytic stomata (irregular celled): The According to number and characterizations of surrounding cells are varying in numbers (4-8), subsidiary cells, the stomata were classified to: have no special arrangement. 1.Anisocytic stomata: surrounded by 3 subsidiary (e.g. Digitalis and Buchu) cells one of them is smaller than the others. (e.g. solanaceae and compositae)  16/11/2024 3. Paracytic stomata (parallel celled): surrounded 4. Diacytic stomta (cross celled): surrounded by 2 by 2 subsidiary cells their long axes parallel to subsidiary cells their long axes perpendicular to the osteole. the osteole. (e.g. Rubiaceae and Senna) (e.g. Labiatae) 5. Actinocytic stomata (star-celled): surrounded by a circle of cells. (e.g Uva ursi)  16/11/2024 2- Mesophyll - It is divided into two layers Mesophyll palisade spongy layer layer - According to the arrangement of the mesophyll, the leaf is described Isobilateral Dorsiventaral leaf leaf Isobilateral leaf Stramonium leaf - The mesophyll is symmetric on Datura leaf both sides showing one or more Thorn apple‫التفاح الشوكى‬ layers of palisade cells on both the upper and lower epidermis. ‫الداتوره‬ Dorsiventaral leaf Origin: - The mesophyll is not It is the dried leaves, with or symmetric showing only one without the flowering tops of palisade layer below the upper epidermis while the Datura stramonium, rest of mesophyll is formed of Family Solanaceae. irregular parenchyma.  16/11/2024 Surface preparation Datura stramonium Leaf 1- The stomata are present on both surfaces but more on the lower, and of the anisocytic type surrounding by 3-5 cells, mostly 3 subsidary cells, one of them is smaller than the other. 2- The hairs are either non-glandular uniseriate - glandular hairs of short stalk and an oval multicellular, of 3-5 cells, slightly curved with warty multicellular head of from 2 to 7 cells which called walls, the basal cell being large. solanaceous hair.  16/11/2024 Microscopical characters T.S diagram Crystal layer= Key element: apart of vein surrounded by parenchyma cells contain cluster of calcium oxalate except adjacent to vein. - The leaf is dorsiventral with a single row of palisade cell on the upper surface. - the lower surface is more prominent than the upper one and the midrib region showing vascular bundle Active Constituents - It contains 0.26 to 0.75% of total tropane alkaloids mainly : hyoscyamine, hyoscine (scopolamine) and Atropine.  16/11/2024 3.Antispasmodic effect in case of intestinal and renal colic. Pharmacological uses It is smooth muscle relaxant (GIT, bladder, ureter). It is used mainly due to the effect of the tropane Hyoscine derivatives are more potent, and most widely used as antispasmodic. alkaloids specially atropine, as following: 4. Smooth muscle relaxant (bronchodilator) 1. CNS stimulant (atropine), respiratory stimulant and relief asthma & relax airway. in large doses leading to restlessness and hallucination. 2. used in ophthalmic practice as mydriatic to dilate the pupil of the eye. Atropine is contraindicated in glaucoma (raised intraocular pressure (IOP). ****Decrease body secretion (sweet, urine,, gastric, salivary, bronchial) Uses of Hyoscine 5. Decreasing the salivary secretions so used as pre- operative drug as pre-anesthetic agent. Hyoscine is better Hyoscine: 6. Decreasing gastric secretions so used in treatment of 1- Sedative. , lack CNS stimulant action peptic and duodenal ulcer. 2-Antiemetic in motion sickness 7. The antidote of choice for overdose or poisoning with 3- Antispasmodic. Physostigmine. 4- pre-anethetic agent 8. Treatment of uncontrolled urination, relax bladder. 9. Treatment of common cold as nasal decongestant, release of epinephrine.  16/11/2024 Chemical tests Chemical tests Specific test for tropane alkaloids General test for alkaloids Shake powder of Stramonium with dil. HCl, filtrate and add Vitali’s Test to the filtrate a drop of Mayer’s reagent. A white or yellowish white ppt. is formed. -Evaporate the alkaloids, cool, add few drops of fuming nitric acid, evaporate on water bath. The residue is cooled and then moistened with few drops of freshly prepared 1) W.B. Dil. HCl Filterate White ppt. alcoholic solution of KOH (10%). Powdered drug + -A violet colour develops which slowly fades away. 2) Filteration Mayer’s reagent Egyptian henbane leaf Surface preparation ‫السكران المصرى‬ 1- The epidermis: Both surfaces have sinuous anticlinal walls and are covered with smooth (upper) and striated Hyoscyamus muticus Origin: (lower) cuticle - The epidermises have anisocytic stomata and carrying It is the dried leaves and flowering tops of glandular trichomes Hyoscyamus muticus Family: Solanaceae Geographical source Egypt  16/11/2024 2- hairs: Glandular hairs with multicellualr uniseriate branched or non-branched stalk and globular unicellular Micromorphology head( branched hair, key element) T.S diagram A transverse section shows that: It has isobilateral structure with 1-3 layers of palisade cells with hairy surfaces powder & isolated elements: 1-Fragments of epidermal cells (upper& lower) 2-Fragments of glandular and non glandular hairs. 3-Prisms and twins of calcium oxalate. 4-Xylem vessels 5-Palisade cells Lower epidermal cells Upper epidermal cells  16/11/2024 Active constituents As Datura leaves Uses As Datura leaves Prisms and twins of Ca.OX Xylem vessels Hyoscyamus branched hairs Palisade cells Hyoscyamus niger Europian Henbane Origin: Active constituents It is the dried leaves and flowering tops of Hyoscyamus niger Hyoscyamine and trace of hyoscine Family: Solanaceae Uses Geographical source 1-Spinal sedative, used in insomnia when opium cannot be given. Europe 2- Relieve gripping caused by purgatives  16/11/2024 ‫ست الحسن‬Belladonna Leaf bella=beautiful, donna=lady Belladonna Origin: It is the dried leaves and flowering tops of Atropa belladonna Family: Solanaceae * Non-glandular hairs are multicellular and Micromorphology uniseriate (2-6 cells) covered with smooth A transverse section shows that: cuticle - It has a dorsiventral structure * Glandular hairs of two types: solanaceous hairs - Both surfaces have wavy with one or two-celled stalk and oval head (2-7 anticlinal walls and are covered with striated cuticle cells) - The epidermises have anisocytic and another type stomata and carrying glandular Multicellular uniseriate and non-glandular trichomes stalk and globular unicellular head Certain cells of mesophyll are filled with microsphenoidal (sandy) crystals of ca. ox.  16/11/2024 Senna Leaf Active constituents compound leaf Alkaloids: Hyoscyamine, hyoscine and atropine Origin: Uses It is the dried leaflets of As Datura leaves Cassia acutifolia (Alexandrian senna) and Cassia angustifolia (Indian senna) Family: Leguminosae Geographical source: Sudan, Egypt Surface preparation Micromorphology 1- Epidermis A transverse section shows that: Epidermal cells have straight walls It has isobilateral structure with single layer of have paracytic stomata on both palisade cells beneath each epidermis continuous in surface in the same number and the midrib region under the upper epidermis may contain mucilage which stain red with ruthenium red reagent. 2- Hairs Non glandular unicellular, conical in shape, covered with thick warty cuticle and curved near the base.  16/11/2024 Powder& isolated elements - Both surfaces have paracytic stomata and non- glandular trichomes Microscopical character 1- Fragment of upper &lower epidermis. 2- Trichomes 3- Calcium oxalate crystals occur as prism in the parenchma cells surrounding groups of pericyclic fibers forming crystal sheath. 4- Palaside cells 5- Xylem vesels 6- Calcium oxalate prisms & clusters Active constituents - Glycosides: anthraquinone derivatives sennoside A, B, C and D - Flavonoids - Mucilage Uses Small dose is laxative while large dose is purgative  16/11/2024 Test for free anthraquinone Substitutes and Adulterants: Add KOH to the powder extract, rose-pink colour is formed Dog Senna (Cassia obovata): Test for combined anthraquinone  The leaves are sometimes broken up and mixed with broken Alexandrian Senna; they may be recognised by the papillosed cells of the lower epidermis. Borntrager's test 1- Boil powdered drug with 10% H2SO4 for 2 minutes to Bombay Senna: hydrolyze the glycoside  The leaflets are usually more elongated and the color is darker. 2- Filter while hot, cool, extract with benzene Cassia auriculata: 3- To the benzene layer add half of its volume with  The thick-walled, unicellular trichomes are about three times as long as those of ammonia, shake well and allow separating, the amonnical the two genuine Senna species and possess a fairly smooth cuticle. layer will take a rose-pink colour Surface preparation ‫اوراق البوكو‬Buchu Leaf 1- Upper epidermis. Formed of large polygonal cells covered with thick cuticle containing mucilage and has moderately Origin: thickened walls It is the dried leaves of Stomata are absent. The cells contain spherocrystals of diosmin which is sol. Barosma betulina (round buchu), in KOH giving yellow colour Barosma crenulata (oval buchu) & Barosma serratifolia (long buchu) Family: Rutaceae  16/11/2024 2- lower epidermis Micromorphology The cells are small, more A transverse section shows that: irregular & the walls are thin & - It has dorsiventral structure with single layer of palisade not beaded. cells continuous in the midrib region Having numerous anomocytic stomata - Both surfaces contain feathery crystals of diosmin (flavonoid glycoside) 3- Hairs Unicellular non glandular, conical in shape & covered with warty cuticle Powder& isolated elements 1- Fragments of upper and lower epidermises carrying non glandular hairs, containing crystals of diosmin; the lower epid. has anomocytic stomata 2- Fragments of palisade cells with chloroplast 3- Fragments of spiral xylem vessels 4- Clusters of ca ox 5- Fragments of schizolysigenous oil glands Schizolysogenous gland 6- non-lignified pericyclic fibers  16/11/2024 Active constituents Diosmin is used for various disorders of blood vessels including hemorrhoids, poor circulation in the legs - Flavonoid Diosmin ,and bleeding (hemorrhage) in the eye or gums. - Volatile oil diosphenol - Mucilage Uses - Diuretic - Urinary tract antiseptic - Increase strength of capillary walls, decrease capillary fragility.. Digitalis Leaf (Foxglove) Chemical test 1- Powder with KOH gives yellow colour (flavonoid) Origin: 2- With Sudan III gives red colour (oil) It is the dried leaves of the flowering 3- With Rhuthenium red gives red colour (mucilage) species of Digitalis purpurea and Digitalis lanata Family: Scrophulariaceae  16/11/2024 Micromorphology Powder of Digitalis purpurea Pale green powder with slight odour and bitter taste Dorsiventeral Microscopically No Calcium oxalate 1- Fragments of upper epidermis with slightly thickened walls and may show slight beading having no stomata or very infrequent 2- Fragments of lower epidermis with thin sinuous walls having anomocytic stomata 3- Non-glandular hairs which are very numerous multicellular, uniseriate (3-5 cells), conical with faintly warted cuticle, one or more of cells are collapsed 4- Glandular hairs which are of two types: one is numerous with single-celled stalk and bicellular head and the less numerous with uniseriate multicellular stalk and unicellular head 5- Fragments of xylem vessels with spiral thickening  16/11/2024 Active constituents Uses Digitalis glycosides 1. It is a cardiotonic. It increases the contractility and improves the tone of the cardiac muscle, both reactions resulting in a slower but much stronger heart beat. Digitalis purpurea and Digitalis lanata. 2. It is used in most forms of cardiac failure. 1. Digitalis purpurea (Red foxglove leaves) Purpurea glycosides A and B 1ry glycoside ) ,digitoxin and gitoxin Chemical test (Keller-Kiliani test) (2ry glycoside) 1. Extract the powder with chloroform. 2. Digitalis lanata (White foxglove leaves) 2. Evaporate to dryness. Lanatosides A, B, C and D 3. Dissolve the residue in glacial acetic acid containing traces of FeCl3. 4. Transfer to test tube, add conc. H2SO4 on the wall. An intense blue colour develop at the surface between the two layers. Chemical identification Squill‫بصل العنصل‬ 1- Keller-Killiani test (for digitoxose) Origin: It is the sliced and dried scale-leaves of Urginea maritima Family: Liliaceae 2- Tests for five membered lactone ring: A- Baljet test: B- Kedde`s test: 3- Microsublimation test: Powder gives brown and colorless droplets and very fine acicular crystals which strongly polarize the light  16/11/2024 Surface Preparation: Micromorphology The epidermis consists of axially elongated quadrangular - The T. S. shows scattered V. B. embedded in or polygonal tabular cells with stomata are present on undifferentiated parenchyma enclosed between the the lower (outer) surface in very small number and epidermises rarely on upper (inner) surface. - Anomocytic stomata are present No hairs - Bundles of raphides of calcium oxalate embedded in mucilage are resent in the parenchyma cells 2- Fragment of upper and lower epidermis Powder &isolated elememts 3- Xylem vessels 1-Very abundant raphides of calcium oxalate occur in bundles embedded in mucilage and scattered throughout the powder key element Epidermal cells with anomocytic stomata Xylem vessels  16/11/2024 Active constituents Uses 1- Cardiac glycosides: Scillaren A and B, Proscillaridin A Like digitalis (cardiotonic & diuretic) 2- Mucilage Expectorant and in chronic bronchitis 3- Sinistrin (carbohydrates) Large dose cause emesis Chemical test - For mucilage: with coralin soda ……. Red colour Red Squill Uses it is used as a rat poison (scilliroside), because It is a variety of Urginea maritima rodents lack the vomiting reflex, which makes The red colour is due to the presence of anthocyanin red squill particularly lethal to these animals. Contain cardiac glycoside scilliroside and glucoscilliroside; proscillaridin A and scillaren A as in the white variety  16/11/2024 Henna ‫الحنة‬ Active constituents The dried leaves of Lawsonia alba F.: Hydrolysis Lawsone Glycosides (2-hydroxy-1,4-naphthoquinone) Lythraceae Flavonoids Coumarins Xanthones Chemical test Lawsone dissolve in alkaline aqueous solution, gives Intense orange red color. Test for flavonoids: yellow colour with KOH Coloring and cosmetic ingredient (hair Uses and nail color) for its strong binding of lawsone to hair Fungicide Used for decoration of feet and hands. Treatment of skin disorders, burns, wounds Treatment of diarrhea the lawsone gradually diffuses into the outer layers of the skin and binds to Taenicide proteins (keratin) present in the skin Antiepileptic cells and hair). Abortifecient agent (induces abortion)  16/11/2024 Black tea ‫الشاى‬Tea Leaves 1- spread on trays 2- rolled (between 2 flat surfaces) 3- fermented, enzymatic oxidation (at temp 20-27◦C) enzymes sensitive to temperature. Yellow color (Complex of alkaloids +tannins) Tannins will converted by oxidase enzyme to insoluble reddish brown phlobaphene (oxidation) 4- drying at 65◦C Origin Black tea Prepared leaves of Thea sinensis (Camillia thea) F.: Theaceae Leaves 1- Roasted in pans heated by direct fire (destroy enzymes, so tannin not oxidised) 2- Cooled 3- rolled Green tea ---------------------- contains higher percent of tannins  16/11/2024 Active constituents Chemical test Alkaloids (purine type) :Caffeine, traces of theobromine and theophylline Test for alkaloids: Mayer’s negative Murexide test (caffeine) Tannins o 5ml of alkaloid in dish, evaporation on W.B. till dryness. In green tea o add few crystals of potassium chlorate and conc. HCl, evaporate on W.B. crimson red colour. o invert the dish on ammonia vapour, give violet colour Volatile oil. add 1 ml of 10% alcoholic NaOH, o Caffeine (disappear of violet colour) o theobromine (no destruction of violet color) Uses Stimulant on the nervous system and heart (caffeine) so used for headache Diuretic (theobromine) Green Tea Increases Fat Burning Smooth muscle relaxant, relief and prevent bronchial asthma antioxidant (theophylline)  16/11/2024 ‫الكوكا‬Coca leaf Active constituents Three alkaloids 1- ecgonine (cocaine) 2- tropine 3- hygrine Test for alkaloids: Mayer’s positive: alkaloid+Mayer’s reagent white turbidity Uses Local anaesthetic (cocaine HCl) Traditional medical uses of coca as stimulant to overcome could stop signal transmission in nerves fatigue, hunger. control severe pain associated with ophthalmic, It is considered particularly effective against altitude sickness ear , nose and throat surgery. (headache, fatigue, stomach illness, dizziness, and sleep toxic and addictive properties disturbance due to decrease oxygen and pressure) People chew coca leaves or inhaled cocaine  16/11/2024 ‫بولدو‬Boldo Active constituents 1- Alkaloids (isoquinoline type, boldine) 2- Volatile oil 3- Flavonoid glycosides ‫عنب الديب‬Uva- ursi Uses Bearberry, bears grape Diuretic Dried leaves of Arctostaphylos uva-ursi F.: Ericaceae Choleretic activity (increase the volume of secretion of bile from the liver) Total alkaloidal extract has greater choleretic activity than boldine alone Diaphoretic an agent that promotes sweating (detoxification) Flavouring agent bile increases the absorption of fats, it is an important part of the absorption of the fat-soluble substances, such as the vitamins A, D, E, and K.  16/11/2024 Constituents Test Test for tannin: violet with FeCl3 Phenolic glycoside (arbutin and ericolin) Arbutin yields hydroquinine and glucose upon hydrolysis with HCl Sublimation test o Gas to solid stage without passing through liquid stage Flavonoids o On crucible, put powder and cover with slide, Triterpenoids heat on direct flame. Tannins o Hydroquinone sublimation needles Uses 1- antiseptic activity (urinary disinfectant) ‫هماميلس‬Hamamelis leaves Dried leaves of Hamamelis virginiana F.: Hamamelidaceae 2- diuretic activity (caution need to replenish potassium) 3- Arbutin, is effective in the topical treatment of hyperpigmentations. Melanin production was inhibited significantly by arbutin.  16/11/2024 Active constituents Uses Tannins (derived from gallic acid) Astringent and haemostatic (tannins) so used in: Bitter principle Application to bruises ‫ الكدمات‬and wounds Ingredient of eye lotions Haemorrhoidal products Treatment of insect bites and teething preparations. Jaborandi leaf It is the dried leaflets of Pilocarpus jaborandi F.: Rutaceae Under ideal storage conditions, the leaves lost at least half of their alkaloids in one year through deterioration. Leaves that are 2 years old are worthless.  16/11/2024 Active constituents: Uses Alkaloid (imidazole): Pilocarpine (nitrate or hydrochloride) Antagonist to atropine Isopilocarpine, pilosine , isopilosine used in ophthalmic practice They cause contraction of the pupil of the eye (miotic) Chemical identification Treatment of glaucoma (as it decreases the intraocular pressure IOP) Helch’s test Induce salivation Diaphoretic Rosemary ‫اكليل الجبل أو حصالبان‬ Constituents Dried leaves of Rosmarinus officinalis F.: Labiateae Volatiole oil Uses. For digestion problems (flatulence) Fragrant spice  16/11/2024 ‫نعناع فلفلى‬Peppermint Mentha Dried leaves and flowering tops of Mentha piperita F.: Labiateae (Lamiaceae) Flavor for chewing gums, tooth paste, mouth wash Active constituents and confectionary products Volatile oil Uses Used as expectorant Carminative Counterirritant An externally applied substance that causes irritation or mild inflammation of the skin for the purpose of relieving pain in muscles and joints  16/11/2024 ‫الريحان‬Sweet basil Active constituents Dried leaves of Ocimum basilicum F.: Labiateae Volatile oil Uses Digestive ‫بردقوش‬Sweet marjoram Active constituents Dried leaves of Origanum majorana F.: Labiateae Essential oil. Uses bronchial disease Functional dyspepsia Relive symptoms of common cold such as nasal decongestant For oral hygiene  16/11/2024 Eucalyptus ‫ يوكالبتوس‬-‫الكافور‬ Inverted V.B. Schizogenous oil Dried leaves of Eucalyptus globulus F.: Myrtaceae gland Active constituents Uses Volatile oil Astringent  Present in oil glands Antiseptic (oil) Tannin Treatment of respiratory disorders , expectorant Bitter principle resin Chemical test: Test for V.O. Red color with sudan III Test for tannins: violet color with FeCl3  16/11/2024 GUAVA LEAVES Volatile oil tannins Flavonoid Uses Astringent Antiseptic in respiratory tract in cough