Types and shapes of leaves. Amir A..pptx
- Количество слайдов: 13
қ ҚР ДЕНСАУЛЫ САҚТАУ МИНИСТРЛІГІ С. Ж. АСФЕНДИЯРОВ АТЫНДАҒЫ ҚАЗАҚ ҰЛТТЫҚ МЕДИЦИНА УНИВЕРСИТЕТІ THE MINISTRY OF HEALTH OF THE RK KAZAKH NATIONAL MEDICAL UNIVRSITY NAMED AFTER S. D. ASFENDIYAROV Compiled by: Amir A. Checked by: Sagantaeva S.
Plan: 1. 2. 3. 4. Arrangement of leaves on stem Shape of leaf Leaf divisions Leaf edges or margins
Plants have leaves in many different shapes - the thicker the book you refer to, the more leaf shapes they seem to find, but here are some of the basic ones. Simple leaves are those that are not compound, or divided into separate parts. These leaves generally have two sections, with the stem dividing the leaf into two even parts. An example of these leaves is Cercis canadensis. Compound leaves have secondary units that branch out from the stem. They can be pinnately compound (Fraxinus Americana), with leaflets arranged on both sides of the stem; palmately compound (Aesculus hipocastanum), with three or more leaflets fanning out from the top of the stem; or bipinnately compound (Gleditsia triacanthos), where primary leaflets are divided into secondary leaflets.
Arrangement of leaves on stem Basal or rosette- all leaves come from the base of the plant Alternate - 1 leaf emerges at each leaf node, they are spaced alternately up the stem Opposite - 2 leaves emerge from each node on opposite sides of the stem Whorled - more than 2 leaves at a node, spaced around the stem Opposite (oppositifolia) Leaves opposite one another Alternate (alternifolia) Arranged alternately Whorled Rosette In circles round the stem Leaves in close rings
Shape of leaf Linear - much longer than it is wide, and roughly the same width throughout Lanceolate - longer than it is wide but wider at the base than the tip Oblanceolate - like lanceolate, but tapering at the base and wider at the tip Oblong - roughly twice as long as broad, with near parallel sides Elliptic - oblong but ends narrowing Ovate - egg-shaped, broader at the base Obovate - egg-shaped, broader at the tip Cuneate - wedge shaped, broad at the tip Spatulate - spoon shaped, oblong but tapering at the base Needle-shaped - short, but long and pointed, as found in pines Awl-shaped - like those on cacti, where the spines are the true leaves
Sword-shaped (ensiformis) Long, thin, pointed Elliptic (elliptica) Oval, with a short point Lance-shaped (lanceolata) Long, wider in the middle Oblanceolate (oblanceolata) Top wider than bottom Ovate (ovata) Oval, with a tapering point Spathulate (spathulata) Spoon-shaped
Round (rotundifolia) Circular Cordate (cordata) Heart-shaped Spear-shaped (hastata) Pointed, with barbs Rhomboid (rhomboidalis) Diamondshaped Lobed (lobata) With several points
Leaf divisions Pinnate - leaflets are arranged along the sides of a central leaf stalk, with or without an end leaflet Bi-pinnate - the main leaflets are again divided into secondary leaflets Palmate - the leaflets are arranged so that they spread out like fingers from a single point at the base of the leaf stalk.
Bipinnate Pinnate (bipinnata) (pinnata) Each leaflet also 2 rows of leaflets pinnate Tripinnate (tripinnata) Each leaflet divided into 3 Pinnatisect (pinnatifida) Cut, but not to the midrib
Trifoliate (trifoliata) Divided into 3 leaflets Perfoliate (perfoliata) Stem through the leaves Palmate (palmata) Divided into many lobes Digitate (digitata) Divided into 5 lobes
Leaf edges or margins Entire - smooth, even line Serrate - sharp, saw-like teeth pointing forward Dentate - toothed, but larger teeth pointing directly outwards Crenate - teeth are short and rounded at the tip, scalloped Undulate - leaf margin forms a wavy line Sinuate - like undulate but much more wavy Incised - cut into sharp, deep irregular incisions Lobed - deep, rounded incisions, but not extending more than half way to the centre of the leaf Cleft - like lobed but incisions extend beyond half way Deeply lobed - very deep incisions, almost to the mid-rib or base of the blade
Literature: 1. Liddell, Henry George; Scott, Robert (1940). Botane (βοτάνη). Oxford: Clarendon Press via Perseus Digital Library, Tufts University. 2. www. google. com
Types and shapes of leaves. Amir A..pptx