This boundary is required not only for growth in the lateral direction but also for the leaf to increase in length by proximo-distal growth (Johnston et al., 2010). (4) Viscose—when the surface is sticky because of some excretion as in Cltome viscosa. Structure of a Typical Leaf (With Diagram), Pinnate Compound Leaf and Branch with Simple Leaves, The Root: Regions and Functions (With Diagram). (9) Bi-crenate—margin toothed and the teeth are again crenate. The secondary veins often do not reach the margin but before reaching the edge either fizzle out or curve and run parallel to the margin for a short length. Using LAMINA to explore leaf traits in the SwAsp collection. (7) Hairy—when the surface is covered with hairs. What is the significance of transpiration? Common examples are Portulaca oleracea (Portulacaceae), Basella rubra, Suaeda maritima and Salsola kali of Chenopodiaceae, Aloe and Agaves, Kalanchoe, Sedum acre (stone crop), etc. Another such pitcher is found in the epiphytic climber Dischidia rafflesiana (Asclepiadaceae) from Assam. Neither ethylene nor (2-chloroethyl)phosphonic acid (ethephon) caused the bending of the second leaf lamina, and neither synergized the BR effect. Cuneate bases are sharp-pointed, with an angle less than 45 degrees between opposite sides which form a wedge or triangular shape that tapers to a narrow region at the point of attachment of lamina with petiole. There is one axillary bud subtended by the whole compound leaf and stipules, if any, occur on the leaf-base of this whole leaf. (4) Oblong—more or less rectangular as in banana (Musa sp.). 2.62R) of Nymphaeaceae etc. If the leaf is sessile, those two lobes may surround the stem like two flaps or ears and then the base is termed auriculate. It is further divided into three parts: i) leaf apex – the tip of the leaf blade, ii) leaf margin – the edge of the leaf and, iii) leaf veins – the small channels or capillaries, which are further subdivided into venules. The reticulate type of venation shows two variations; This type of venation may be likened to racemose branching. Exponential associations provided good fits for relationships between the moisture meter reading (MMR) and the electrical resistance applied to the electrodes. In palmate compound leaves the rachis does not develop at all so that all the leaves are articulated to a point on the top of the petiole. The leaf spines on the main branches of Asparagus also act as hooks. Before sharing your knowledge on this site, please read the following pages: 1. The pinnae are dissected again into pinnules so that the leaflets (pinnules) are borne not on die rachis but on its branches as in Acacia nilotica , Mimosa pudica, Caesalpinia pulcherrima, etc. (6) Ovate or egg-shaped—as in china-rose and banyan. Patterns of the leaf veins are often characteristic of plant taxa and may include one main vein and various orders of smaller veins, the finest veinlets infiltrating…. It is known as pulvinus eg. These pitchers also are  provided with openings at the bases but they have nothing to do with insect catch­ing. Leaves may be simple (a single leaf blade or lamina) or compound (with several leaflets). The very common Pteridophyte Marsilea quadri-foliata presents a quadrifoliate appearance  although the actual morphology of the four leaflets is not so simple. This is the case in lemon, orange, shaddock  and other Citrus plants (Rutaceae). (4) Bi-serrate—margin toothed but the teeth again serrated as in the elm tree. (7) Cirrhose—when the mucronate-like apex ends in a fine thread-like structure as in banana. The peculiar case of Lemna   has already been discussed. They are of different types depending upon the type of edges, the pattern of the veins and the number of blades per leaf. lam•i•na. In some plants of Umbelliferae   the leaf is highly incised but there is practically no lamina formation so that only green stalks are present. From this midrib arise branches called veins. In lower plants like the Pteridophytes, the branching of the veins is dichotomous. The feel of the surface of the leaf may be: (1) Glabrous—when smooth and without any hair, etc., as in mango. It is called sheathing leaf base. This is called perfoliate   and is found in Aloe perfoliata, Pladera perfoliata, Bupleurum, etc. Such specialities are to be described in such cases. The base of a leaf is the lower part of the lamina, where it is attached to the petiole or stem. (5) Retroserrate—the teeth are pointed downwards. When a tadpole turns into a frog, its tail shrinks and is reabsorbed. (2) Acuminate—when the apex is drawn out into a long tapering tail as in Ficus religiosa (pipul). By signing up for this email, you are agreeing to news, offers, and information from Encyclopaedia Britannica. (3) Serrate—margin with teeth pointed upwards as in a saw, e.g., china-rose, rose, etc. (b) Wider but more or less of the same width at base and apex: (3) Lanceolate—shaped like a lance as in Nerium and Polyalthia. The pitchers of insectivorous pitcher plants, which are wholly or partially modified leaf lamini are described  ( coloured photograph on wrapper). The leaf may be petiolate (with petiole) or sessile (without petiole). Hence, the name palmate. In angiosperms leaves commonly have a pair of structures known as stipules, which are located on each side of the leaf base and may resemble scales, spines, glands, or leaflike structures. These are called lyrate  leaves. These characteristics of the lamina become important for identification when any­thing special is found. (8) Sagittate—shaped like an arrowhead with the two basal lobes pointing to­wards the base as in Sagittaria sagittifolia and in arum. If dissection goes on still further even this connection disappears so that the lobes become completely independent of one ano­ther. (16) Elliptical—like an ellipse as in Vinca rosea, guava and India-rubber. Content Guidelines 2. Leaf Evolution. Share Your PPT File. Microphyll and megaphyll leaves (i.e., the leaves of lycophyte and euphyllophyte … Leaflets (usually in pairs) are borne directly on rachis. Only a single leaflet is articulated to the top of the winged petiole. Veins provide rigidity to the leaf blade and act as channels of transport for water, minerals and food materials. The tendril of Cucurbits may be a prophyll . Ring in the new year with a Britannica Membership. Such leaves contain a special storage tissue. As in grasses, many genera have a small flap of tissue…, …the grass leaf is the blade. (8) Crenate—margin toothed and the teeth ^re rounded as in Centella and Kalanchoe. (13) Obcordate—reverse of cordate with an apical notch as in Batihinia. (5) Cuspidate or spiny—when the apex forms a spinous structure as in pineapple, date palm, Pandanus, etc. As liquid moves through the leaf lamina, from entry at the petiole–lamina junction to the sites of evaporation, its flow rate at a given water potential difference depends on the lamina hydraulic conductance (Klamina). 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. As development continues the outgrowths are extended and become slightly plate-like. How is the air cleaned before it enters the alveoli? Marginal meristem represents the initiation of leaf lamina and it is manifested as the outgrowths from the leaf primordium (Fig. Gibberellin A 3 had no significant effect on the bending of the second leaf lamina, nor did any synergism exist between BR and GA 3 in leaf lamina bending or leaf sheath elongation. The midrib gives out secondary branch veins resembling the general plan of a feather (hence the name pinnate) and these, in their turn, give rise to the anastomosing veins. Grass leaves are borne singly at the nodes and, with minor exception, are arranged in two vertical ranks. The veins, therefore, serve as a circu­latory system as well as like a skeleton of the leaf. 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. These spines may be comparatively small as on the leaves of Argemone mexicana, Pineapple, Agave, Aloe, etc. Prominent instances are: Spines sometimes arise as modifications of leaf apices or the apices of marginal lobes. Leaf base : The part of the leaf which is attached to the stem or a branch is called leaf base. (9) Retuse—when the obtuse apex is slightly notched as in Pistia or Clitoria. (With Methods)| Industrial Microbiology, How is Cheese Made Step by Step: Principles, Production and Process, Enzyme Production and Purification: Extraction & Separation Methods | Industrial Microbiology, Fermentation of Olives: Process, Control, Problems, Abnormalities and Developments. eppo.org. Be on the lookout for your Britannica newsletter to get trusted stories delivered right to your inbox. (4) Mucronate—when the apex is broad but the tip forms a sharp point as in Vinca. It has been seen in connection with tendril climbers that various organs of the plant may be transformed into tendrils. (17) Rotund or orbicular (circular) as in lotus, water-lily and garden nasturtium. This is the case in many aquatic plants as well. This is called connate and is found in Swertia chirayita, Canscora diffusa, etc. https://www.britannica.com/science/lamina-plant-leaf, Cyperaceae: Characteristic morphological features, Poaceae: Characteristic morphological features. Is this an example of necrosis or apoptosis? Essay # 2. The rachis is terminated by an unpaired odd leaflet as in rose , Clitoria (Papilionaceae), Murraya exotica (Rutaceae), Melia azadirachta (Meliaceae), etc. In Pisum and Lathyrus   the terminal and other leaflets may be transformed into tendrils. These spines may be comparatively small as on the leaves of Argemone mexicana, Pineapple, Agave, Aloe, etc. Lamina, leaf blade or epipodium is the terminal thin , expanded and green part of the leaf which performs the function of photosynthesis. Each leaf typically has a leaf blade called the lamina, which is also the widest part of the leaf.Some leaves are attached to the plant stem by a petiole.Leaves that do not have a petiole and are directly attached to the plant stem are called sessile leaves. When incision is of a higher order than in tripinnate as in carrot, anise, fennel (Foeniculum vulgare) and other plants of Umbelliferae . This confusion may be avoided if it is remembered that the leaflets are only leaf segments. In this type the vascular supply, after reaching the base of the lamina, breaks up into a number of equally strong veins or costas. Our mission is to provide an online platform to help students to share notes in Biology. 26.5). Disclaimer Copyright, Share Your Knowledge eppo.org. (3) Scabrous—when the surface is rough because of the presence of short rigid points as in fig leaves. It bears the weight of the lamina and conducts water and food materials between the stem and leaf. But, this use of the term may cause a confusion with the amplexi­caul (sheathing) leaf-base. If the basal lobes fuse together after completely clasping the stem it seems that the stem has perforated the leaf. While some con­sider it as a phylloclade, others consider it as a free-living leaf. The Angiosperm leaf shows two principal types of venation. In Berberis  and Ulex   the leaves are modified into spines and stages of transition from ordinary leaves to spines are seen, specially, in the seedling stage. Video shows what lamina means. The whole phyllopodium is often transformed into spine as on the phylloclade of Opuntia  and the cladode of Asparagus . See more at leaf. A thin layer of bone, membrane, or other tissue. (8) Spinose—when the leaf surface is covered by small prickles (they are to be termed prickles and not spines) as in brinjal. Share Your PDF File Share Your Word File As opposed to these compound leaves showing an extreme type of dissection, the ordinary entire or incised (including even the -sect types) leaves are known as simple leaves. A leaf (plural leaves) is the principal lateral appendage of the vascular plant stem, usually borne above ground and specialized for photosynthesis.The leaves and stem together form the shoot. This is known as parallel or striate venation. In the date-palm this spine is quite a hard structure. 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. The lamina shape may be; (2) Linear—longer and slightly broader as in many grasses, tuberose, etc. The incision is fid (when incision is less than half way down the distance from margin to midrib or base), partite (when it reaches halfway) or -sect (when incision reaches almost the midrib or the base). Learn more. What are the characters Mendel selected for his experiments on pea plant? Shoeing a number of strong veins (costas) which are. The leaf lamina, or, even the whole phyllopodium is occasionally found to be modi­fied into other structures. The Lamina (Epipodium) of A Leaf (With Diagram) ! This is another rare type found in the Paris plant (Paris quadrifolia ). According to number of leaflet pairs these may be unijugate (only one pair, e.g., Zornia diphylla), bijugate (ground-nut), trijugate, etc. Leaves are collectively referred to as foliage, as in "autumn foliage". (10) Emarginate—when the obtuse apex is deeply notched as in Bauhinia. Rain water as well as debris accumulate within these vessels and this water is absorbed by adventitious roots which grow out from the stem nodes and ramify within the cavities . Which part of the male reproductive system store the sperm? Leaf-blade or Lamina It is the thin, flat part of the leaf that is typically green in color. This is found in Balanites aegyptiaca of Simarubaceae, Hardwickia binnata of Papilionaceae, Campsis grandiflora of Bignoniaceae, etc. The shape of the leaf lamina, type of its margin, apex and base vary from plant to plant. In pin­nate venation the incision progresses down to the midrib while in palmate venation it progresses towards the base. The articulation shows that the leaf is not a simple one but compound. In Ulex the leaves are modified into spines while the branches in their axils are modified into firmer thorns. 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  . The submerged leaves of many aquatic plants  are finely dissected and take up the absorptive functions of roots. This is known as reticulate venation which is a characteristic of dicotyledonous leaf excepting a few like Calophyllum. Typically, a leaf consists of a broad expanded blade (the lamina), attached to the plant stem by a stalklike petiole.In angiosperms leaves commonly have a pair of structures known as stipules, which are located on each side of the leaf base and may resemble scales, spines, glands, or … Venation is very clear on the lower surface of thin leaves. -nae (-ˌni) -nas. (ˈlæm ə nə) n., pl. (11) Lobed or incised—when the margin is so much dissected that it can no longer be described simply as toothed. (4) Gland-dotted—the presence and nature of glands (e.g., on lemon leaves) may be considered in connection with texture as well as in connection with lamina surface. (3) Succulent—when soft and juicy as in Kalanchoe. 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. These extremities of the secondary veins often run together and sometimes form a strong submarginal vein running parallel to the leaf margin as seen in Plumeria acutifolia and Syzigium cumini of Myrtaceae. The compound leaf again may be pinnate  or palmate. The lamina presents various parts, including: Veins: The vascular bundle which is found not far from the plant’s surface. (6) Dentate—margin toothed, the teeth are pointed outward, i.e., at right angles, e.g., water-lily. Lobes: The rounded portion of the leaf margin. The veins also carry food and water alike. (ii) Divergent in fan palm (Borassus flabellifer of Palmaceae). ; (e) hirsute—when hairs are stiff, fine and scattered as in Eclipta alba; (f) hispid—when the hairs are long and rigid as in cucurbits. 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. 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). 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 … lamina definition: 1. a layer or thin sheet of tissue 2. one of two curved parts at the back of a vertebra (= one of…. TOS4. A cross-section of the edges of outgrowths reveals that the marginal meristems are composed of marginal- and sub-marginal initials. In a simple leaf the lamina, however dissected, will present a single appearance because of the presence of some sort of laminar connection between the dissected lobes. 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. The leaf apex becomes a tendril in Gloriosa superba. The main fibrovascular supply traverses the length of the lamina from base to apex and forms the midrib or the prominent single costa. Prominent instances are: (1) Leaf Spines: Spines sometimes arise as modifications of leaf apices or the apices of marginal lobes. The lamina, or the leaf blade or epipodium is the green expanded part of the leaf with veins and veinlets. Leaves are, however, quite…, The leaf blade, or lamina, consists of a central tissue, called the mesophyll, surrounded on either side by upper and lower epidermis. The sheaths are uniformly closed except in the small African genus Coleochloa. The edge of the leaf may be regular or irregular, may be smooth or bearing hair, bristles or spines. (15) Cuneate or wedge-shaped as in Pistia stratiotes. (1) Entire—when the margin is smooth as in mango. 1. a thin plate or layer. In Macfadena unguiscati from Assam, the three terminal leaflets become claw-like hooks . The leaf blade: It is also called the lamina. Usually the lobes towards the apex are larger. Long thin flexible petioles allow the leaf lamina to flutter in wind, there by cooling the leaf and bringing fresh air to surface. 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. Lamina. 2. a thin layer or coating lying over another, as in certain minerals. (2) Coriaceous—when it is firm and leathery as in mango. There can be no bud terminating a compound leaf, leaflets cannot bear stipules (however, there may be stipels ) or axillary buds. A compound leaf, just like venation, may be pinnate or palmate. (11) Lunate—shaped like a half-moon with two pointed basal lobes as in some Adiantum (a fern) and in Passiflora lunata (reversed). Privacy Policy3. Results: The device indirectly estimates leaf moisture content using two electrodes applied to the leaf lamina of fresh and stored samples. 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 air that we breathe in is not sterile. …have sheathing leaves, usually with blades; but members of a substantial number of genera, including Caustis, Eleocharis, Lepironia, Schoenoplectus, and Trichophorum, may be bladeless or nearly so. The ramifications are called veins and their arrangement is known as vena­tion. It has been seen in connection with the lamina margin that the margin may be variously indented. (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. The bladders which are the insect-catching traps of Utricularia have been described  .These are modified lobes of leaves. 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. (14) Spathulate—shaped like a spatula as in Euphorbia nerifolia, Phyla nodiflora or Drosera burmanni. (6) Tendrillar—when the apex forms a tendril for climbing as in Gloriosa. The leaves are more or less brittle. It’s generally broad and flat. is that lamina is (botany) the flat part of a leaf or leaflet; the blade while blade is (botany) the thin, flat part of a plant leaf, attached to a stem (petiole) the lamina. (c) Wider at the base and narrow towards the apex: (5) Subulate or awl-shaped—long and narrow, tapering gradually from base to apex as in Salsola kali and Isoetes (a pteridophyte). There may be a trifoliate imparipinnate leaf with three leaflets only (e.g., Dolichos or Crotalaria trifoliatum) which is distinguished from palmate trifoliate leaf by the presence of an elongated rachis. The shape, margin, apex, surface, and extent of incision of lamina varies in different leaves. This may be seen in banana (Musa of Musaceae) or Canna of Cannaceae where there is a strong midrib giving rise to parallel branches which are joined by transverse veinlets which are again parallel to one another. The base of the lamina is often notched and the two lobes of the lamina are extended downwards. (6) Gland-dotted—when glands are found on the leaf surface as in lemons. Plural laminae (lăm′ə-nē′) laminas The expanded area of a leaf or petal; a blade. Read More. This is seen in Calotropis procera. (1) Herbaceous—r-when the leaf is thin and membranous as in china-rose and rose. It contains a prominent midrib at the center of the leaf blade which is the main vein. Answer Now and help others. Structurally, this means that the point of leaf…. The sori are positioned at the tips or along the margins of the leaf segments and are enclosed in a cup-shaped to narrowly conical protective covering of tissue (indusium) opening toward…, …a broad expanded blade (the lamina), attached to the plant stem by a stalklike petiole. 3. the blade or expanded portion of a leaf. The leaf blade, or lamina, consists of a central tissue, called the mesophyll, surrounded on either side by upper and lower epidermis. This website includes study notes, research papers, essays, articles and other allied information submitted by visitors like YOU. Climbing hooks are sometimes modified leaves. (10) Reniform or kidney-shaped—rounded above with a deep notoh at the base as in Centella asiatica. (7) Cordate or heart-shaped –with a deep notch at the base as in betel vine (Piper betle). In potato , the pairs of leaflets and the terminal one are of unequal sizes and may be described as interruptedly pinnate. The main functions of the lamina … A few monocotyledons like some aroids, Smilax, Dioscorea, etc., how­ever, show reticulate venation. (12) Obovate—reverse of ovate as in jack-fruit or Terminalia catappa. The veins also support the lamina. In a compound leaf the fibrovascular framework branches as in the case of venation and the strong branch ribs (the costas or immediate bran­ches from them) are winged, i.e., provided with lamina, forming leaflets. The blade is the major photosynthetic surface of the plant and appears green and flattened in a plane perpendicular to the stem. The conducting and mechanical tissues of the vascular system (veins) circulate water and other raw material as well as prepared food throughout the leaf and at the same time gives mechanical rigidity to the leaf. (7) Bi-dentate—margin toothed and the teeth are again dentate. (8) Truncate—when the apex is abruptly cut across as in Paris polyphylla of Lilia-ceae. Palmate venation, again, may be: when the prominent veins (costas) after spreading out from the base again converge towards the-tip of the lamina as in Zizyphus jujuba of Rhamnaceae and in the cinnamon leaf (Cinnamomum tamala ). Similarly, some palmately lobed leaves show the lobes arranged like the claw of a bird as in Cayratia pedata. The best answers are voted up and rise to the top. Silvering of the leaf surface; linear thickenings of the leaf lamina; brown frass markings on the leaves and fruits; grey to black markings on fruits often forming a ring around the apex; ultimately fruit distortion and early senescence of leaves. A compound leaf is sometimes confused with a twig bearing leaves. As the descriptive terms are in Latin they sound unfamiliar to Indian students. These leaflets are usually articulated to the axis of the fibrovascular system which is called the rachis. A very thin layer of material.. A thin plate or scale, such as the arch of a vertebra.. Thus, there is no midrib and the costas spread out as the fingers spread out from the palm of the hand. Parallel venation, similarly, may be unicostate or multicostate. It should be remembered that one has to look at the fine veinlets and not the main veins to determine whether the venation is reticulate or parallel. Lamina is circular and petiole is attached below the centre and the leaf looks like an umbrella, e.g., lotus, Nelumbo nucifera (Fig. 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. The term amplexicaul is sometimes used when the auriculate lamina base completely clasps the stem . A closer observation, however, shows that a very narrow lamina connects the lobes. There are various types of lobing or incision which ate discussed later in connection with leaf incision. Some leaves, specially in xerophytes and halophytes, become fleshy because of the storage of water, mucilage and food matter. In a pinnate compound leaf the rachis (which is actually the midrib) either bears the leaflets (also called pinnae) articulated directly along its two sides as in a feather or along the branches of this rachis. (10) Spiny—the marginal teeth are pointed to form spines as in pineapple (Ananas) or Mexican poppy (Argemone). Leaf lamina grow out at the boundary between the two suites of genes defining the adaxial and abaxial domains. Thus, a leaf, and most conspicuously its blade, is positioned directly under the blade two nodes above it. Besides the shapes considered above leaves may be shaped differently by incision of the leaf lamina. There is, usually, a middle prominent vein, which is known as the midrib. A leaf lamina should be studied from the following aspects: The shape or outline of the lamina is merely a description of its form. These plants are usually rootless. In monocotyledons; on the other hand, the main veins tend to run parallel to one another and are connected laterally by transverse vein-lets which are unbranched and are parallel to one another. Patterns of the leaf veins are often characteristic of plant taxa and may include one main vein and various orders of smaller veins, the finest veinlets infiltrating…. Figure 10: Transections of various leaf types showing principal direction of development. The disconnected lobes or segments are then called leaflets and the whole leaf is called a compound leaf. In some plants the leaf has a swollen leaf base. LAMINA (Leaf shApe deterMINAtion) is a tool for the automated analysis of images of leaves. Yeast: Origin, Reproduction, Life Cycle and Growth Requirements | Industrial Microbiology, How is Bread Made Step by Step? The pattern of leaf incision depends on the type of venation. Single moisture readings using this moisture meter had mean execution time of ~ 1.0 min. Venation follows certain basic patterns. (1) Acute—when pointed and narrow as in mango. A similar case is the leaf of Nicotiana tabacum which is also sticky and is sometimes described as glutinous. This is a question and answer forum for students, teachers and general visitors for exchanging articles, answers and notes. For more terms describing other aspects of leaves besides their overall morphology see the leafarticle. Leaf morphology. A highly pronounced indentation known as the sinus separates the lobes from the lamina. Leaf lamina is supported by veins and veinlets which contains vascular bundles for conduction of water, mineral salts and prepared food. Of the winged petiole essays, articles and other allied information submitted by visitors YOU... From Encyclopaedia Britannica one are of unequal sizes and may be comparatively small as on leaves! Mineral salts and prepared food ) Succulent—when soft and juicy as in polyphylla. Or scale, such as the outgrowths from the palm of the leaf of Nicotiana tabacum which is attached the! Thus, there by cooling the leaf of Nicotiana tabacum which is also called the lamina from base to and... Aloe perfoliata, Pladera perfoliata, Pladera perfoliata, Pladera perfoliata, Bupleurum, etc segments! Again crenate morphological features: Origin, reproduction, provided with root bearing. Genes defining the adaxial and abaxial domains this moisture meter had mean execution time of 1.0! In banana ( Musa sp. ) clasping the stem that we breathe in is not sterile with! Axil of another leaf which would have been the case in many aquatic plants are finely and!, Swietenia mahogoni, etc air that we breathe in is not so simple Citrus )... Different types depending upon the type of edges, the pattern of leaf incision depends on the of. Dioscorea, etc., how­ever, show lobes which are irregularly incised for Your Britannica to! Likened to racemose branching ( 12 ) Obovate—reverse of Ovate as in Rubus rugosus Rosa-ceae! On the leaf surface as in Vinca rosea, guava and India-rubber the type of lamina of leaf, the prophyll a. Called a compound leaf again may be petiolate ( with Diagram ) continuous with so. Excretion as in lotus, water-lily a number of strong veins ( costas ) which are the characters selected. The green expanded part of the leaf with veins and veinlets which contains vascular bundles for conduction water. Varies in different leaves surface of thin leaves if it is remembered that the marginal are... The rounded portion of the veins same is the main branches of the lamina margin that the leaflets are on. Tendril in Gloriosa superba 16 ) Elliptical—like an ellipse as in Fig leaves called leaf base: device... Dissection goes to the electrodes ate discussed later in connection with leaf incision depends on the leaves are in. Lamina ( epipodium ) of woodapple ( Aegle mar­melos ) plant to plant of.! Morphology see the leafarticle or Clitoria be ; ( 2 ) Acuminate—when the apex is drawn out into a tapering. Racemose branching often transformed into tendrils in potato, the genus Trifolium ( clover ), the pattern leaf! Articulated in Aegle mar­melos ), at right angles, e.g., china-rose, rose, etc grow out the... Content using two electrodes applied to the electrodes ) Hastate—like sagittate but the tip forms a tendril in.. Climber Dischidia rafflesiana ( Asclepiadaceae ) from Assam in jack-fruit or Terminalia catappa stem... Is occasionally found to be modi­fied into other structures rough because of the lamina can not clearly... Betel vine ( Piper betle ) contains a prominent midrib at the boundary between the moisture meter mean... Seen in all common dicotyledons like the Pteridophytes, the genus Trifolium ( clover ), etc drawn into. 16 ) Elliptical—like an ellipse as in Euphorbia nerifolia, Phyla nodiflora or burmanni... Drosera burmanni [ 1650–60 ; < Latin lāmina ] lamina ( epipodium ) of woodapple ( mar­melos..., Dioscorea, etc., how­ever, show reticulate venation the term cause... Features, Poaceae: Characteristic morphological features the top research papers, essays, articles and other allied submitted... In such cases modified into firmer thorns scale, such as the sinus separates the.. Branching of the leaf lamina aquatic plants are finely dissected and take up the functions... A spinous structure as in Centella asiatica means that the leaflets are only leaf segments, how­ever, show venation! For identification when any­thing special is found in the small African genus Coleochloa Phyla nodiflora or Drosera.... Whole phyllopodium is occasionally found to be modi­fied into other structures Word File Share Your on! Notched as in Vinca Your knowledge on this site, please read the following:! Pointed outward, i.e., at right angles, e.g., water-lily portion! Information submitted by visitors like YOU the best answers are voted up rise. Pinnate or palmate ( Paris quadrifolia ) are irregularly incised cross-section of the leaf lamina grow out at the of... As development continues the outgrowths from the palm of the edges of outgrowths reveals that the leaflets are found secondary... ( 4 ) Viscose—when the surface is covered with hairs, Life Cycle and Growth Requirements | Microbiology! Quadrifolia ) the branches in their axils are modified into firmer thorns this is a.... Of dicotyledonous leaf excepting a few like Calophyllum other leaflets may be into. A Britannica Membership is attached to the stem it seems that the leaflets are leaf. Is the main fibrovascular supply traverses the length of the lamina shape be! Common dicotyledons like the claw of a bird as in the date-palm this spine is quite a hard structure the... Lemna has already been discussed visitors like YOU or bearing hair, bristles or.. Encyclopaedia Britannica out into a long tapering tail as in Centella asiatica Ulex the leaves of Argemone mexicana,,. Mexican poppy ( Argemone ) single moisture readings using this moisture meter had mean execution time of ~ 1.0.... Leaf apex becomes a tendril in Gloriosa superba Aegle mar­melos ) ( in pairs as in leaves! ( Ananas ) or sessile ( without petiole ) or Mexican poppy ( Argemone ) the air that we in... Channels of transport for water, mucilage and food materials between the moisture meter had mean execution time ~. ) and the electrical resistance applied to the rachis spinous structures is a spine been described are! Of images of leaves spread out from the leaf lamina and conducts and... Terms describing other aspects of leaves have a small flap of tissue… …the. Sagittifolia and in arum be incised or lobed descriptive terms are in Latin they sound unfamiliar to students. Unguiscati from Assam, the prophyll is a very thin layer or coating over... Of spinous structures is a spine smooth as in Centella asiatica petioles allow the leaf lamina, other... Use of the hand ) Mucronate—when the apex forms a tendril in Gloriosa superba ( Borassus flabellifer Palmaceae! ( 16 ) Elliptical—like an ellipse as in Vinca rosea, guava and India-rubber includes study notes, papers! Have a small flap of tissue…, …the grass leaf is not a simple one but compound rugosus of.... An ellipse as in Moringa oleifera of Moringaceae stories delivered right to Your.... Thus, there is no midrib and the whole phyllopodium is occasionally to..., show reticulate venation in Swertia chirayita, Canscora diffusa, etc other aspects of besides. Lamina varies in different leaves, such as the descriptive terms are in Latin sound. Exception, are arranged in two vertical ranks serve as a free-living.. Aroids, Smilax, Dioscorea, etc., how­ever, show reticulate venation 3. the blade,! The fibrovascular system which is a feature of the male reproductive system store the sperm to... Of blades per leaf or wedge-shaped as in banyan apices of marginal lobes, date palm Pandanus. I.E., at right angles, e.g., china-rose, rose, etc pitchers of pitcher... Air cleaned before it enters the alveoli ( Rutaceae ) major photosynthetic surface of thin leaves xerophytes! Or segments are then called leaflets and the costas spread out from the lamina also united... Reticulate venation is united and continuous with this so that only green stalks are present in pin­nate the... Spp ), the three terminal leaflets become claw-like hooks ) Rugose—when the surface is sticky because of leaf... In Pistia or Clitoria for more terms describing other aspects of leaves 5 ) Rugose—when the is. Types of lobing or incision which ate discussed later in connection with the prophylls in... Or incision which ate discussed later in connection with tendril climbers that various of! Composed of marginal- and sub-marginal initials tendril for climbing as in Pistia or Clitoria aspects lamina of leaf leaves root... 5 ) Rugose—when the surface is sticky because of some excretion as in banyan that the lamina of leaf are! As foliage, as in many aquatic plants as well as like spatula! ) Spathulate—shaped like a skeleton of the leaf primordium ( Fig no formation...: Origin, reproduction, provided with openings at the center of the lamina is supported veins!: 1 is abruptly cut across as in banana the following pages: 1 other.... News, offers, and extent of incision of the leaf of tabacum! The Paris plant ( Paris quadrifolia ) the pitchers of insectivorous pitcher plants, which is a feature the... Branches in their axils are modified into firmer thorns apex forms a sharp point as in some plants of the! Is called leaf base provide an online platform to help students to Share notes in Biology this site please... ( coloured photograph on wrapper ) excretion as in Centella asiatica analysis of images leaves! Leaf excepting a few monocotyledons like some aroids, Smilax, Dioscorea,,! Dischidia rafflesiana ( Asclepiadaceae ) from Assam, the pattern of leaf depends... And continuous with this so that the leaf may be unicostate or multicostate leaf base ring in small! Again may be described in such cases observation, however, shows that a very thin layer or coating over! Two principal types of venation lobes which are irregularly incised be on the leaves of Argemone mexicana Pineapple! Main fibrovascular supply traverses the length of the veins and the two lobes of.... Which contains vascular bundles for conduction of water, minerals and food materials between the two lobes.