Slide 1 Leaves LHAP 104 Landscape Horticulturist 1 Botany Slide 2 Photo credit Photos that have a Figure reference number are taken from The Molecular Life of Plants.www.wily.com/go/jones/molecularlifeofplants Other photos were taken from public domain sites as indicated on the slides or from personal photographs. Slide 3 Leaves main solar collectors for the plant usually contain chlorophyll chlorophyll traps light energy leaves get carbon dioxide (CO2) from the air water for the leaves comes from the roots the trapped light energy is converted to chemical energy and is stored as sugar photos-public-domain.com Slide 4 Photosynthesis: Leaves manufacture food for the plant commons.wikimedia.org Chlorophyll Slide 5 Chlorophyll cells that can trap the sun’s energy have chlorophyll Chlorophyll is a green pigment that is contained in chloroplasts Slide 6 Slide 7 http://phsgirard.org/APbiology/Chapter35/LeafStructure.jpg (should be clear in colour) (should be clear in colour) Slide 8 Morphology & Anatomy Slide 9 Epidermis single layer of cells covering the leaf surface has a thin layer of waxy cutin called the cuticle The epidermis does NOT contain chlorophyll (should be clear in diagram) http://phsgirard.org/APbiology/Chapter35/LeafStructure.jpg (should be clear in colour) (should be clear in colour) Slide 10 Stomata each stomata is made up of one stoma (pore) surrounded by two long guard cells stomata are openings that allow CO2 from the air to enter the leaf (and unfortunately water is lost to the atmosphere) the guard cells contain chlorophyll to provide energy to open and close most plants have stomata on the underside of the leaf Slide 11 Slide 12 Fig. 14.29 Slide 13 Slide 14 Transpiration water loss through the stomata Slide 15 Transpiration this is the driving force for water movement in the xylem water is “pulled” up by tension generated by the evaporation of water from the leaf stomata called the “cohesion-tension-transpirational pull theory” forums.gardenweb.com Slide 16 Mesophyll meso = “middle” phyll = “leaf” Palisade mesophyll is the upper layer of cells just below the epidermis contains over 80% of the chloroplasts Spongy mesophyll are cells with lots of air space between them - loosely packed and rounded allows for CO2 to move in and water vapour to move out http://phsgirard.org/APbiology/Chapter35/LeafStructure.jpg Slide 17 Leaf miners leaf miners are insects that feed on the tissues that are between the epidermis layers https://takluyver.files.wordpress.com Slide 18 Veins found in the mesophyll area xylem & phloem are surrounded by fibres called the bundle sheath veins are the transport system of the leaf: sugars move into the phloem and water & minerals are brought to the leaf cells from the roots by the xylem photos-public-domain.com Slide 19 Specialized leaves shade leaves leaves for arid regions tendrils reproductive leaves floral bracts insect trapping leaves 74211.com free wallpaper Slide 20 Shade leaf vs Sun leaf shade leaves are thinner and larger to capture as much light as possible under shaded condition chloroplasts are stained red Slide 21 Leaves for arid regions thick leathery leaves fewer stomata or sunken stomata to reduce transpiration http://www.public-domain-image.com/free-images/nature-landscapes/deserts/botany-landscapes-desert-forest-scenics-725x475.jpg Slide 22 Tendrils actually modified leaves tendrils help to support weak stems www.gardeners.com Slide 23 Reproductive leaves plantlets form on the margins of existing leaves www.britannica.com Slide 24 Floral bracts these red “petals” are actually leaves Slide 25 Insect trapping leaves upload.wikimedia.org/wikipedia/commons publicdomainpictures.net