There are two types of palmately reticulate venation: When the main veins diverge towards the margin of the leaf. All rights reserved. E.g., Palmyra palm. Here stipules are modified into spines. Multiflora Rose, Rosa multiflora Multiflora Rose has leaves with 7-9 toothed leaflets and fringed stipules, per Woody Plants of the Blue Ridge. The veins are chiefly made of vascular tissues, the xylem and phloem. E.g., Rose. Types of Leaves 3. Leaf base often contains two small lateral outgrowths called stipules. Stipules: The position of stipules on a plant leaf varies from species to species, though they are located near the base of a leaf. E.g., Lathyrus. See more. It is a leaf in which the secondary rachii are branched to form tertiary rachii which in turn bear the leaflets. This gives off lateral veins which reach the margin or apex of the leaf. Parallel venation is divided into two types depending upon the number of principle veins: In this type of venation, the leaf has a prominent midrib and this gives off lateral veins which precede parallel to each other towards the margin or apex of the leaf-blade. A leaf is said to be simple when it consists of a single blade which may be entire or incised (and, therefore, lobed) to any depth, but not cut down to the mid-rib or the petiole. In this type two stipules lie between the petioles of opposite or whorled leaves. A leaf which bears a number of leaflets which seem to be radiating from a common point on the tip of the petiole. In the pitcher plant Nepenthes, a terrestrial insectivorous plant, the lamina gets modified into a pitcher-like structure. When the veins spread upward in a curved manner and converge towards the apex. A pair of leaves at one node stands directly over the lower pair in the same plane. The modification of tap roots consists in the enormous swelling and enlargement of the primary root with slender hair like lateral or branch roots. E.g., silk cotton tree (Bombax). The veins arise from the tip of the petiole, diverge and reach the margin of the leaf-blade in a more or less parallel manner. The leaf base is expanded to form a laminar structure to carry out photosynthesis. A leaf is said to be compound when the incision of the leaf-blade goes down to the midrib (rachis) or to the petiole so that the leaf is broken up into a number of segments, called leaflets. When five or more leaflets are joined to the tip of the petiole and are spreading like fingers from the palm. those plants which live fer two years and within this period they are to face favourable and unfavourable seasons; in the unfavourable season the upper part dies; next year’s growth is completed at the expense of food stored in the modified root. (f) Cordate-When the two lobes of the leaf base gives a heart-shaped appearance. E.g., Ficus, Magnolia. A number of more or less equally strong veins proceed from the leaf base and converge towards the leaf apex. a small paired usually leaflike outgrowth occurring at the base of a leaf or its stalk. E.g., Ixora, madar (Calotropis). Unabridged E.g., Hibiscus, mustard. across the cell membrane. Sergey Ivanovitch was all the while admiring the beauty of the woods, which were a tangled mass of leaves, pointing out to his brother now an old lime tree on the point of flowering, dark on the shady side, and brightly spotted with yellow, Certain plants excrete a sweet juice, apparently for the sake of eliminating something injurious from their sap: this is effected by glands at the base of the, En effet, les deputes de la premiere Chambre comme les conseillers de la deuxieme sont appeles a mettre au point les projets de loi en suspens et surtout les lois organiques qui devraient etre examinees et approuvees avant la fin du mandat de l'actuelle coalition gouvernementale comme le, They have simple opposite leaves, with interpeciolar, Le porte-parole du Cabinet, Dr Omar Mohammed Salih a declare a la presse que la Convention, Dictionary, Encyclopedia and Thesaurus - The Free Dictionary, the webmaster's page for free fun content, 66 candidats pour la presidentielle anticipee du 15 septembre en Tunisie recales, Archeveque d'Alger: "il n'y a pas de probleme de liberte de culte en Algerie", Parlement : une session marathonienne en vue, ENVIRONMENTAL SCANNING ELECTRON MICROSCOPY (ESEM) OF Morinda citrifolia L. (Rubiaceae) COLLETERS, Tunis : Marzouki convoque le corps electoral, Le Cabinet approuve la Convention de l'ONU sur la lutte contre la corruption, Dette US: Obama signe la loi mettant fin au shutdown, Choura : La loi sur la protection des temoins approuvee. surrounding and clasping the twig). (b) Cuneate-When leaf base becomes narrow to broad wedge-like taper, acute and the sides become straight. Foliaceous: Present in the form of a large leaf, e.g., Lathyrus aphaca. E.g., Grasses, wheat, bamboo. 6. Endocytosis is the process by which materials are transported into the cells by the formation of vesicles. A. A leaf with four leaflets articulated to the tip of the petiole. On the basis of their structure and relation to the leaf, stipules may be of the following types: The two stipules are free and are borne on the two sides of the leaf base. The stipules may be either attached to the leaf base or are present on both sides as lateral outgrowths. (b) Deliquescent :-When the tree takes a dome-shaped (more or less rounded) appearan, Roots Modified Roots: Both tap roots and adventitious roots may be modified for carrying out special functions- either physiological or mechanical. E.g., Murraya. STRONG STEM :- Plants become erect and remain in an upright position due to the rigidity of the stem, as seen in herbs, shrubs and trees. It is green in colour and carries out photosynthesis. The leaf Stipules :A stipule is the outgrowth of the hypopodium or leaf base. Phyllotaxy 5. Opposite Stipules If the stipules of a leaf fuse by their outer margins in a position opposite to the leaf attachment, the fusion product is described as an opposite stipule (e.g., Ficus elastica). (d) Obtuse-When the leaf base is round and constricting abruptly to the petiole, (e) Truncate-Here the leaf base with a nearly straight line across the bottom, as if cut across. Modifications. Storage Roots- These roots become fleshy and swollen due to the accumulation of food stored in roots. The leaf apex is modified into a lid. E.g., rangoon creeper (Quisqualis). Why Are A, E, I, O, U, And Y Called “Vowels”? E.g., Polygonum. Stipules are often variously patent (i.e. E.g., rose. E.g., Michelia champaca. In Gloriosa superba the leaf apex is modified into a tendril. Such a leaf is said to be tripinnate. E.g., Tabernaemontana. one of a pair of lateral appendages, often leaflike, at the base of a leaf petiole in many plants. Interpetiolar: Present in between the petioles of opposite or whorled leaves, e.g., Mussaenda. Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012. There are three principal types of phyllotaxy: Here a single leaf is produced at each node alternately on the stem. When there are more than two leaves at each node which are arranged in a circle or a whorl. E.g., Ixora, Mussaenda. E.g., Opuntia. All content on this website, including dictionary, thesaurus, literature, geography, and other reference data is for informational purposes only. They are present in many families of dicotyledons, but they are absent or very rare in monocotyledons. Leaves with stipules are called stipulate and those without are called exstipulate. Leaf is said to be stipulate when the stipule is present, while in its absence the leaf is estipulate. Aerial stems may be (a) strong (erect) or (b) weak. E.g., Balanites, Hardwickia. Modified tap roots A) MODIFIED TAP ROOTS- For physiological funtions (storage of foods) : 1. species of Abies, Picea, Pinus (Gymnosperms), Polyalthia longifolia (Anonaceae) etc. In Calotropis procera, the leaf is sessile, here the two lobes surround the stem like two flaps and the base is called auriculate. Here two leaves are produced at each node opposite to each other. “Affect” vs. “Effect”: Use The Correct Word Every Time. Venation in Leaves 2. The three types of stipules according to duration are caducous, deciduous and persistent. The arrangement of the leaves in various modes at the nodal region of the stem is called phyllotaxy. Reticulate venation is divided into two types depending upon the number of the principle veins. © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins E.g., peepul (Ficus), mango (Mangifera).