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lamina of leaf

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The lamina presents various parts, including: Veins: The vascular bundle which is found not far from the plant’s surface. The edges of the leaf lamina are called the margins; the point, at which the margins meet the petiole, is called the lamina base, and the tip of the lamina is known as the apex. Thus, there is no midrib and the costas spread out as the fingers spread out from the palm of the hand. Long thin flexible petioles allow the leaf lamina to flutter in wind, there by cooling the leaf and bringing fresh air to surface. Sometimes the bases of opposite leaf laminas become fused together when the two leaves look like one through the centre of which the stem passes  . It has already been seen that in the decurrent type   the petiole as well as the leaf-base and a part of the stem are winged and united. The entire lamina becomes a tendril in Lathyrus while the terminal leaflets are so transformed in Pisum , Naravelia zeylanica (Ranunculaceae) and Bignonia venusta. The pattern of leaf incision depends on the type of venation. (2) Glaucus—when the surface is covered by a waxy coating causing a shiny bluish or whitish tinge as in the leaves of lotus, arum or Calotropis. Neither ethylene nor (2-chloroethyl)phosphonic acid (ethephon) caused the bending of the second leaf lamina, and neither synergized the BR effect. This is called perfoliate   and is found in Aloe perfoliata, Pladera perfoliata, Bupleurum, etc. The Lamina (Epipodium) of A Leaf (With Diagram) ! Leaf Evolution. (5) Cuspidate or spiny—when the apex forms a spinous structure as in pineapple, date palm, Pandanus, etc. Another such pitcher is found in the epiphytic climber Dischidia rafflesiana (Asclepiadaceae) from Assam. In extreme cases of leaf incision (e.g., date palm or marigold leaf) it seems that the lobes have been completely dissected so that there is no laminar connection between the lobes. In pin­nate venation the incision progresses down to the midrib while in palmate venation it progresses towards the base. As nouns the difference between lamina and blade is that lamina is a very thin layer of material while blade is the sharp cutting edge of a knife, chisel, or other tool, a razor blade. Parallel venation, similarly, may be unicostate or multicostate. 2. a thin layer or coating lying over another, as in certain minerals. The base of a leaf is the lower part of the lamina, where it is attached to the petiole or stem. (9) Bi-crenate—margin toothed and the teeth are again crenate. It is known as pulvinus eg. (6) Dentate—margin toothed, the teeth are pointed outward, i.e., at right angles, e.g., water-lily. (4) Viscose—when the surface is sticky because of some excretion as in Cltome viscosa. If there be more than four leaflets as in the silk- cotton tree (Bombax ceiba of Bombacaceae ), Cleome viscosa and Cleome gynandra of Capparidaceae, horse chestnut (Aesculus hippocastanum), etc. Welcome to BiologyDiscussion! Single moisture readings using this moisture meter had mean execution time of ~ 1.0 min. (10) Reniform or kidney-shaped—rounded above with a deep notoh at the base as in Centella asiatica. The disconnected lobes or segments are then called leaflets and the whole leaf is called a compound leaf. (8) Truncate—when the apex is abruptly cut across as in Paris polyphylla of Lilia-ceae. This is known as reticulate venation which is a characteristic of dicotyledonous leaf excepting a few like Calophyllum. Using LAMINA to explore leaf traits in the SwAsp collection. (7) Hairy—when the surface is covered with hairs. (2) Acuminate—when the apex is drawn out into a long tapering tail as in Ficus religiosa (pipul). Dissection goes to the third order so that the leaflets are found on secondary branches of the rachis as in Moringa oleifera of Moringaceae . The leaf blade, or lamina, consists of a central tissue, called the mesophyll, surrounded on either side by upper and lower epidermis. A leaf lamina should be studied from the following aspects: The shape or outline of the lamina is merely a description of its form. Develop­ment of spinous structures is a feature of the xerophytes. Leaf lamina grow out at the boundary between the two suites of genes defining the adaxial and abaxial domains. Leaflets (usually in pairs) are borne directly on rachis. La lamina nucléaire est un maillage fibrillaire dense bordant (côté nucléoplasme) l'enveloppe nucléaire d'une cellule.Il s'agit d'un réseau protéique fibreux, homologue aux filaments intermédiaires qui double la membrane interne de l'enveloppe nucléaire formant une couche de 10 à 20 nm d'épaisseur et interrompue par des pores nucléaires. There can be no bud terminating a compound leaf, leaflets cannot bear stipules (however, there may be stipels ) or axillary buds. (ii) Divergent in fan palm (Borassus flabellifer of Palmaceae). Lobes: The rounded portion of the leaf margin. The articulation shows that the leaf is not a simple one but compound. If the leaf is sessile, those two lobes may surround the stem like two flaps or ears and then the base is termed auriculate. A cross-section of the edges of outgrowths reveals that the marginal meristems are composed of marginal- and sub-marginal initials. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? The main functions of the lamina … The rachis is terminated by an unpaired odd leaflet as in rose , Clitoria (Papilionaceae), Murraya exotica (Rutaceae), Melia azadirachta (Meliaceae), etc. (10) Spiny—the marginal teeth are pointed to form spines as in pineapple (Ananas) or Mexican poppy (Argemone). (14) Spathulate—shaped like a spatula as in Euphorbia nerifolia, Phyla nodiflora or Drosera burmanni. In order to test LAMINA and to provide us with an overview of leaf characteristics within the SwAsp collection to guide future experimental design, we sampled leaves from the northern common garden of the SwAsp collection [].As we had previously used ImageJ [] for analysing leaf area, we first performed a comparison analysis … In the first type the strong main veins give rise to finer branches which again branch repeatedly running into one another and forming a reticulum or network all over the leaf. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. The fibrovascular tissue system supplying a leaf reaches the base of the lamina through the petiole and from this point it branches out or ramifies according to certain patterns. The reticulate type of venation shows two variations; This type of venation may be likened to racemose branching. This is known as parallel or striate venation. The shape, margin, apex, surface, and extent of incision of lamina varies in different leaves. Lamina, leaf blade or epipodium is the terminal thin , expanded and green part of the leaf which performs the function of photosynthesis. There is, usually, a middle prominent vein, which is known as the midrib. These spines may be comparatively small as on the leaves of Argemone mexicana, Pineapple, Agave, Aloe, etc. There is one axillary bud subtended by the whole compound leaf and stipules, if any, occur on the leaf-base of this whole leaf. (6) Ovate or egg-shaped—as in china-rose and banyan. (13) Obcordate—reverse of cordate with an apical notch as in Batihinia. (1) Entire—when the margin is smooth as in mango. It’s generally broad and flat. These are called pedate  leaves. Lamina is circular and petiole is attached below the centre and the leaf looks like an umbrella, e.g., lotus, Nelumbo nucifera (Fig. Essay # 2. LAMINA (Leaf shApe deterMINAtion) is a tool for the automated analysis of images of leaves. (3) Succulent—when soft and juicy as in Kalanchoe. As in grasses, many genera have a small flap of tissue…, …the grass leaf is the blade. When incision is of a higher order than in tripinnate as in carrot, anise, fennel (Foeniculum vulgare) and other plants of Umbelliferae . (4) Oblong—more or less rectangular as in banana (Musa sp.). This is another rare type found in the Paris plant (Paris quadrifolia ). How is the air cleaned before it enters the alveoli? (3) Scabrous—when the surface is rough because of the presence of short rigid points as in fig leaves. Leaf base : The part of the leaf which is attached to the stem or a branch is called leaf base. In this type the vascular supply, after reaching the base of the lamina, breaks up into a number of equally strong veins or costas. The presence and persistence of water on the leaf lamina is a phenomenon that can be more or less evident and can affect crop performance. Modifications of the Leaf Lamina: The leaf lamina, or, even the whole phyllopodium is occasionally found to be modi­fied into other structures. Privacy Policy3. The base of the lamina is often notched and the two lobes of the lamina are extended downwards. The leaf blade: It is also called the lamina. (7) Bi-dentate—margin toothed and the teeth are again dentate. These plants are usually rootless. …and are characterized by a lamina (leaf blade) that is usually only one cell layer thick between the veins. (7) Cirrhose—when the mucronate-like apex ends in a fine thread-like structure as in banana. The best answers are voted up and rise to the top. The lamina shape may be; (2) Linear—longer and slightly broader as in many grasses, tuberose, etc. Leaf-blade or Lamina It is the thin, flat part of the leaf that is typically green in color. (9) Hastate—like sagittate but the two basal lobes are directed outwards as in some Ipomoea and in Typhonium. In the date-palm this spine is quite a hard structure. Similarly, some palmately lobed leaves show the lobes arranged like the claw of a bird as in Cayratia pedata. If the basal lobes fuse together after completely clasping the stem it seems that the stem has perforated the leaf. Figure 10: Transections of various leaf types showing principal direction of development. The leaf apex becomes a tendril in Gloriosa superba. (2) Coriaceous—when it is firm and leathery as in mango. The term amplexicaul is sometimes used when the auriculate lamina base completely clasps the stem . Thus, according to the pinnate  or the palmate  type of venation the incision may be (1) pinnatifid (e.g., poppy or chrysanthemum leaf); (2) pinnatipartite (e.g., Argemone mexicana); (3) pinnatisect (e.g., marigold, date palm, coconut, Ipomoea quamoclit); (4) palmatifid (passion flower or cotton leaf); (5) palmatipartite (castor or papaw leaf) and (6) palmatisect (Ipomoea pulchella or Tapioca leaf). eppo.org. A thin layer of bone, membrane, or other tissue. Leaves evolved independently multiple times [], and the evolution of flat leaves and leaflike organs has played a central role in optimizing photosynthesis, with profound environmental consequences for life on Earth.Liverworts and mosses have leaflike enations that lack vascular tissues. The sheaths are uniformly closed except in the small African genus Coleochloa. Common examples are Portulaca oleracea (Portulacaceae), Basella rubra, Suaeda maritima and Salsola kali of Chenopodiaceae, Aloe and Agaves, Kalanchoe, Sedum acre (stone crop), etc. These again may be of many types: (a) pubescent—when the hair is soft and woolly as in tomato; (b) pilose—when the hairs are long, distinct and scattered as in Grewia flavescens; (c) villose—when hairs are long, soft and closely arranged as in Leucas aspera; (d) tomentose—when hairs are short, dense and cottony as in Terminalia tomentosa, Calolropis procera, etc. https://www.britannica.com/science/lamina-plant-leaf, Cyperaceae: Characteristic morphological features, Poaceae: Characteristic morphological features. The Angiosperm leaf shows two principal types of venation. It is called sheathing leaf base. It contains a prominent midrib at the center of the leaf blade which is the main vein. This is called connate and is found in Swertia chirayita, Canscora diffusa, etc. The main fibrovascular supply traverses the length of the lamina from base to apex and forms the midrib or the prominent single costa. Answer Now and help others. Which part of the male reproductive system store the sperm? In monocots the leaf base is very broad and flat and it clasps a part of the node of the stem as in maize in banana. If dissection goes on still further even this connection disappears so that the lobes become completely independent of one ano­ther. Prominent instances are: Spines sometimes arise as modifications of leaf apices or the apices of marginal lobes. Leaflets are borne in pairs as in Tamarindus indica , different species of Cassia, Swietenia mahogoni, etc. ) Dentate—margin toothed, the pairs of leaflets and the teeth are again dentate formation that. Of radish or mustard, show reticulate venation transformed into tendrils woodapple ( Aegle ). 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In china-rose and banyan said to be incised or lobed this connection disappears so that the is... Of another leaf which would have been described.These are modified into spines while the in... Email, YOU are agreeing to news, offers, and extent of incision of lamina varies in different.... The boundary between the stem interruptedly pinnate the part of the lamina important...

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