Leaf Morphology PDF

Introduction of leaves I- Morphology 1  Leaf Leaf: Lateral outgrowth from the stem differs in structure and function Leaf apex Leaf margin Consists of three parts: Leaf lamina Leaf petiole...

Introduction of leaves I- Morphology 1  Leaf Leaf: Lateral outgrowth from the stem differs in structure and function Leaf apex Leaf margin Consists of three parts: Leaf lamina Leaf petiole Bud Leaf base Venation Midrib Leaf Leaf petiole lamina Leaf base 2  Scheme for description of Leaf morphology 1. Name: English, Latin and Arabic names 2. Origin: Part used, name of plant, family name Fresh or dry 3. Condition: Entire or broken pieces 4. Colour: As seen in bulk 3  5. Insertion Cauline Radical Leaves are arranged Leaves are arranged on elongated stem on a discoid stem crowded on top of root eg: Carrot. 4  6. Phyllotaxis Arrangement of leaves on the elongated stem Alternate Opposite One leaf on each node Two leaves on the same node opposite to each other 5  Opposite decussate Whorled Two leaves opposite Three or more leaves each pair is perpendicular on each node to the pair above and below 6  7. Leaf base a. Stipules b. Sheath c. Other Characters a. Stipules Lateral projection at the leaf base For protection of the axillary bud May be hairy, leafy or spiny Present Absent Stipulate Exstipulate 7  Stipules Hairy Leafy Spiny 8 b. Sheath 9  8. Leaf petiole a. Occurrence b. Characters c. Pulvinous a. Occurrence Petiolate Sessile 10  b. Characters Short Long petiole 11  Colour Green purple12 Shape: Cylindrical, quadrangular, flattened Cylindrical flattened 13 Glabrous Pubescent (to the naked eye) 14  Grooved to the upper surface Characters of petiole: size, colour, shape, surface, grooved or not 15  c. Pulvinous: Swelling at the base of the petiole for adjustment of movement towards light, may be present or absent 16  9. Lamina a. Composition Simple Lobed Compound 17  Simple leaf With continuous undivided surface 18  Compound leaf The leaf is divided into leaflets Binate Ternate Palmate Pinnate Five or more Several Two leaflets Three leaflets leaflets leaflets arising from arranged in the top of the pairs on a petiole. rachis. 19  Pinnate Paripinnate Imparipinnate The leaf ends with The leaf ends with a pair of leaflets a single leaflet 20 21  b. Incision for Lobed Pinnate Palmate One main midrib More than one main midrib arising from the top of the petiole Pinnatifid Pinnatipartite Pinnatisect Palmatifid Palmatipartite Palmatisect 22 Pinnatifid Pinnatipartite Pinnatisect 23 Palmatifid Palmatipartite Palmatisect 24 c. Shape Elliptical Ovate Cordate Lanceolate Oblanceolate Linear25 Spathulate Obovate  d. Size: Length and width Ciliate e. Margin Serrate Entire Sinuate Dentate Crenate 26 f. Apex Acute acuminate obtuse emarginate apiculus 27 truncate mucronate  g. Base Symmetric Asymmetric ± Decurrent 28  h. Venation Parallel venation Reticulate venation The veins are parallel to the midrib ± Pinnate reticulate Palmate reticulate Anastomosing vennation 29  i. Surface Upper Lower Colour Glabrous (to the Colour (paler Glabrous (to the naked eye) or or the same) naked eye) or pubescent pubescent + The midrib prominance: The midrib is more prominant to the lower surface (or Equally prominent to both surfaces). Glabrou pubescent Lower s Upper 30 j. Texture Papery Leathery or coriaceous Succulent or fleshy k. Odour Aromatic Characteristic l.Taste Bitter Mucilaginous Salty Characteristic 31 32 33 34