query: where are the stomata usually found on a leaf

pos: Stoma and participatory plant breeding to find the best suited species such as heat and drought resistant crop varieties that could naturally evolve to the change in the face of food security challenges. Stoma In botany, a stoma (plural "stomata"), also called a stomata (plural "stomates") (from Greek στόμα, "mouth"), is a pore, found in the epidermis of leaves, stems, and other organs, that facilitates gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening. The term is usually used collectively to refer

pos: Justicia adhatoda When a leaf is cleared with chloral hydrate and examined microscopically the oval stomata can be seen. They are surrounded by two crescent-shaped cells at right angles to the ostiole. The epidermis bears simple one- to three-celled warty hairs, and small glandular hairs. Cystoliths occur beneath the epidermis of the underside of the blade. The trunk has many, long, opposite, ascending branches, where the bark is yellowish in color. Flowers are usually white and the inflorescence shows large, dense, axillary spikes. Fruits are pubescent, and are with club-shaped capsules. The leaves of "Adhatoda vasica" contains phytochemicals such as alkaloids, tannins,

pos: Epidermis (botany) the leaves of monocots than in those of dicots. Trichomes or hairs grow out from the epidermis in many species. In root epidermis, epidermal hairs, termed root hairs are common and are specialized for absorption of water and mineral nutrients. In plants with secondary growth, the epidermis of roots and stems is usually replaced by a periderm through the action of a cork cambium. The leaf and stem epidermis is covered with pores called stomata (sing., stoma), part of a stoma complex consisting of a pore surrounded on each side by chloroplast-containing guard cells, and two to four subsidiary cells

pos: Stoma Stoma In botany, a stoma (plural "stomata"), also called a stomata (plural "stomates") (from Greek στόμα, "mouth"), is a pore, found in the epidermis of leaves, stems, and other organs, that facilitates gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening. The term is usually used collectively to refer to the entire stomatal complex, consisting of the paired guard cells and the pore itself, which is referred to as the stomatal aperture. Air enters the plant through these openings by gaseous

pos: Stoma and participatory plant breeding to find the best suited species such as heat and drought resistant crop varieties that could naturally evolve to the change in the face of food security challenges. Stoma In botany, a stoma (plural "stomata"), also called a stomata (plural "stomates") (from Greek στόμα, "mouth"), is a pore, found in the epidermis of leaves, stems, and other organs, that facilitates gas exchange. The pore is bordered by a pair of specialized parenchyma cells known as guard cells that are responsible for regulating the size of the stomatal opening. The term is usually used collectively to refer

neg: Stoma number of stomata on both leaf surfaces. In plants with floating leaves, stomata may be found only on the upper epidermis and submerged leaves may lack stomata entirely. Most tree species have stomata only on the lower leaf surface. Leaves with stomata on both the upper and lower leaf are called amphistomatous leaves; leaves with stomata only on the lower surface are hypostomatous, and leaves with stomata only on the upper surface are epistomatous or hyperstomatous. Size varies across species, with end-to-end lengths ranging from 10 to 80 µm and width ranging from a few to 50 µm. Carbon dioxide,

neg: Abies numidica Abies numidica Abies numidica (Algerian fir) is a species of fir found only in Algeria, where it is endemic on Djebel Babor, the second-highest mountain (2,004 meters) in the Algerian Tell Atlas. "Abies numidica" is a medium-sized to large evergreen tree growing to 20–35 meters tall, with a trunk up to 1 meter diameter. The leaves are needle-like, moderately flattened, 1.5–2.5 centimeters long and 2–3 millimeters wide by 1 millimeters thick, glossy dark green with a patch of greenish-white stomata near the tip above, and with two greenish-white bands of stomata below. The tip of the leaf is variable, usually

neg: Stomatal conductance Stomatal conductance By definition, stomatal conductance, usually measured in mmol m⁻² s⁻¹, is the measure of the rate of passage of carbon dioxide (CO) entering, or water vapor exiting through the stomata of a leaf. Stomata are small pores on the top and or bottom of a leaf that are responsible for taking in and expelling CO and moisture from and to the outside air. The rate of stomatal conductance, or its inverse, stomatal resistance, is directly related to the boundary layer resistance of the leaf and the absolute concentration gradient of water vapor from the leaf to the atmosphere.

neg: Stomatal conductance pressure deficit, formula_30 is the leaf-surface CO concentration, formula_31 is the CO compensation point. formula_32 and formula_33 are empirical coefficients. Stomatal conductance By definition, stomatal conductance, usually measured in mmol m⁻² s⁻¹, is the measure of the rate of passage of carbon dioxide (CO) entering, or water vapor exiting through the stomata of a leaf. Stomata are small pores on the top and or bottom of a leaf that are responsible for taking in and expelling CO and moisture from and to the outside air. The rate of stomatal conductance, or its inverse, stomatal resistance, is directly related to the

neg: Epidermis (botany) that lack chloroplasts. The stomata complex regulates the exchange of gases and water vapor between the outside air and the interior of the leaf. Typically, the stomata are more numerous over the abaxial (lower) epidermis of the leaf than the (adaxial) upper epidermis. An exception is floating leaves where most or all stomata are on the upper surface. Vertical leaves, such as those of many grasses, often have roughly equal numbers of stomata on both surfaces. The stoma is bounded by two guard cells. The guard cells differ from the epidermal cells in the following aspects: At night, the sugar

neg: Stoma However, dry climates are not the only places where they can be found. The following plants are examples of species with stomatal crypts or antechambers: "Nerium oleander", conifers, and "Drimys winteri" which is a species of plant found in the cloud forest. Stomata are obvious holes in the leaf by which, as was presumed for a while, pathogens can enter unchallenged. However, it has been recently shown that stomata do in fact sense the presence of some, if not all, pathogens. However, with the virulent bacteria applied to "Arabidopsis" plant leaves in the experiment, the bacteria released the chemical coronatine,

neg: Taphrina caerulescens over guard cells and enter the leaf tissue through open stomata. Two germ tubes may even form from the same spore, the second protruding from the opposite end of the cell. This is the only known method of entry by "T.caerulescens", no direct penetration or appresoria have been observed in this species. Thus, infection occurs only on the underside of leaves, where stomata are found. In the saprophytic stage the single celled spores grow like yeast, that is to say they bud (replicate) directly. Spores may be disseminated by wind or rain. These cells then overwinter and serve as inoculum

neg: Afrocarpus in texture. They have a single visible midrib. Stomata are found on both surfaces of the leaf. "Afrocarpus" are dioecious, with male pollen cones and female seed cones borne on separate individual plants. The cones are short pedunculate and usually develop from axillary buds. The male pollen cones are narrowly cylindrical and resemble catkins. They grow in small groups of two or three cones. The peduncles are glabrous. Each pollen cone has numerous spirally inserted microsporophylls each with two basal pollen sacs producing bisaccate pollen. The female seed cones are solitary. Their peduncles may have small scale leaves. The cones

neg: Selaginella apoda axil, sporangia are created from artificial cells. While stomata can be found following the leaf margin on the lower surface of the plant's leaves, stomata on the upper surface of "S. apoda" leaves disperse entirely following the laminae. The dorsal leaves of "S. apoda" have acuminate apices. The primary leaves of "S. apoda" significantly contrast in shape from the cotyledons of the plant. "Selaginella apoda" leaf blades have borders with a margin that is light green in appearance or simply identical to each other. The strobilus of "S. apoda" is often restricted to a length of 1-2 centimeters. Typically, the

neg: Ammophila breviligulata and the rough upper leaf surface, which contains the gas exchange openings (stomata), can orient itself away from wind. Beachgrass is a dominant species on foredunes, and indeed is sometimes the only plant found there. It is much less vigorous further in from the coastline, which is puzzling. Why should a species that competes so well on foredunes be fairly unsuccessful just a few meters further in from the coast, where other plants usually dominate? One mechanism for this effect that has been extensively studied by Wim van der Putten and his colleagues is based on the susceptibility of "Ammophila"

neg: Podocarpus may be sessile or short petiolate. The phyllotaxis or leaf arrangement is spiral and may be subopposite on some shoots. The leaves are usually linear-lanceolate or linear-elliptic in shape, though they can be broader lanceolate, ovate or nearly elliptic in some species. Juvenile leaves are often larger than adult leaves though similar in shape. The leaves are coriaceous and have a distinct midrib. The stomata are usually restricted to the abaxial or underside of the leaf, forming two stomatal bands around the midrib. "Podocarpus" are generally dioecious, with the male pollen cones and female seed cones borne on separate individual

neg: Chloroplast plants such as cacti, chloroplasts are found in the stems, though in most plants, chloroplasts are concentrated in the leaves. One square millimeter of leaf tissue can contain half a million chloroplasts. Within a leaf, chloroplasts are mainly found in the mesophyll layers of a leaf, and the guard cells of stomata. Palisade mesophyll cells can contain 30–70 chloroplasts per cell, while stomatal guard cells contain only around 8–15 per cell, as well as much less chlorophyll. Chloroplasts can also be found in the bundle sheath cells of a leaf, especially in C plants, which carry out the Calvin cycle

neg: Gasteranthus altitudes of up to 1,800 m ASL. The flowers are usually colored in orange hues and often spotted, but background colors also include shades white, yellow and red. They are born in axillary cymes without bracteoles. "Gasteranthus" was previously included in the closely related genus "Besleria". The two genera have been separated on the basis of differences in their stomata (aggregated in "Gasteranthus", scattered in "Besleria") and fruits (fleshy capsule in "Gasteranthus", berry in "Besleria"). Characteristic are the whitish dots on the leaf undersides caused by aggregations of stomata in "Gasteranthus". Two main groups can be distinguished in this genus:

neg: Retrophyllum vitiense the shoot and down on the other side. The leaf blades are usually 15-25 millimeters long, 3-5 millimeters wide and ovate-lanceolate or ovate-elliptic in shape. Juvenile leaves are often larger. The narrow midrib of the leaf is conspicuous on the abaxial side. Stomata are present on both sides of the leaf. "Retrophyllum vitiense" is dioecious. The cylindrical male pollen cones are borne apically on short lateral or subterminal branchlets. They grow in groups of two or three. A pollen cone consists of numerous spirally arranged microsporophylls around a 10-25 millimeter long rachis. The microsporophylls are triangular and keeled, bearing two

neg: Dioon recognizable midrib. The nerves spring directly from the edge of the leaf rhachis and then run towards the plumage axis. The spars are hairy at least on young leaves. The hairs (trichomes) are colorless, branched or simple. The stomata for the gas exchange are found either only on the underside of the leaf, or in some species on both sides. Glands are not otherwise colored and difficult to identify. The cells of the leaf epidermis are extended parallel to the plumage axis. Like other cycads, coral-like roots are sometimes formed that grow up from the primary root and branch out

neg: Tomato leaf mold one year in the absence of a susceptible host. When the condition are favorable the sclerotia produce new conidia, which act as primary inoculum to infect plants. The conidia produce mycelium that infects the plant through stomata when humidity is 85% or higher and produce conidiophores on the abaxial leaf surface of infected leaves. The symptoms usually start to appear 10 days after inoculation with spore formation, a large number of conidia are produced and these spores are easily spread from plant to plant by the wind, splash water, on tools, clothing of workers and also by insects. Spores are

neg: Pinus quadrifolia white endosperm, and a vestigial wing; they are dispersed by the pinyon jay, which plucks the seeds out of the open cones. The jay, which uses the seeds as a food resource, stores many of the seeds for later use, and some of these stored seeds are not used and are able to grow into new trees. The Parry pinyon frequently hybridises with single-leaf pinyon ("P. monophylla") where their ranges meet in southern California and northern Baja California. Hybrids are distinguished by intermediate features, with needles usually fascicles of 2–3 with some stomata on the outer surface. It has been

neg: Leaf complex. The opening and closing of the stomatal aperture is controlled by the stomatal complex and regulates the exchange of gases and water vapor between the outside air and the interior of the leaf. Stomata therefore play the important role in allowing photosynthesis without letting the leaf dry out. In a typical leaf, the stomata are more numerous over the abaxial (lower) epidermis than the adaxial (upper) epidermis and are more numerous in plants from cooler climates. Most of the interior of the leaf between the upper and lower layers of epidermis is a "parenchyma" (ground tissue) or "chlorenchyma" tissue

neg: Ammophila (plant) grass has a rolled leaf that creates a localized environment of water vapour concentration within the leaf, and helps to prevent water loss. The stomata sit in small pits within the curls of the structure, which make them less likely to open and to lose water. The folded leaves have hairs on the inside to slow or stop air movement, much like many other xerophytes (though these are typically found on the outside of the plant, but in marram grass they are also within the leaf as this has now become a structure with more volume). This slowing of air

neg: Banksia novae-zelandiae Banksia novae-zelandiae Banksia novae-zelandiae is an extinct species of "Banksia", known only from fossil leaves found in the South Island of New Zealand. This species is based on several leaf fossils, all with triangular pinnate lobes cut all the way back to the midrib, and indistinct secondary venation. Stomata occur in areoles, and have very wrinkly subsidiary cells. Both leaf surfaces are covered in trichome bases, and the undersurface is covered in cuticular papillae. Fossil leaves were found at the Newvale Mine, Waimumu Coalfield, Southland District, South Island, New Zealand (), in a thin leaf litter bed located in a

neg: Red thread disease Red thread disease Red thread disease is a fungal infection found on lawns and other turfed areas. It is caused by the corticioid fungus "Laetisaria fuciformis" and has two separate stages. The stage that gives the infection its name is characterised by very thin, red, needle-like strands extending from the grass blade. These are stromata, which can remain viable in soil for two years. After germinating, the stromata infect grass leaf blades through their stomata. The other stage is visible as small, pink, cotton wool-like mycelium, found where the blades meet. It is common when both warmth and humidity are

neg: Tomato leaf mold dried leaf. Spores germinate in the leaf surface with free water and humidity with above 85%. This pathogen can survive at least one year without a host which is called non-obligate. The temperature must be between 40°~94 °F (4°~34 °C) for germinating spore. The pathogen usually infects the leaves by penetrating through stomata in a high humidity level. The life cycle starts with the fungus overwintering as sclerotia on plants debris, in seeds and in soils as a saprophyte. Conidia also play an important role as survival structure, once that it are resistant to drying, and might survive up to

neg: Agroinfiltration leaf. The "Agrobacterium" suspension is then injected into the airspaces inside the leaf through stomata, or sometimes through a tiny incision made to the underside of the leaf. Vacuum infiltration is another way to introduce "Agrobacterium" deep into plant tissue. In this procedure, leaf disks, leaves, or whole plants are submerged in a beaker containing the solution, and the beaker is placed in a vacuum chamber. The vacuum is then applied, forcing air out of the intercellular spaces within the leaves via the stomata. When the vacuum is released, the pressure difference forces the "Agrobacterium" suspension into the leaves through

neg: Ruppia medium-sized. Their disposition can be alternate, opposite, or whorled (usually alternate except when subtending an inflorescence). Even, lamina keep entire and are setaceous or linear. The leaf just shows one vein without cross-venules. Stomata are not present. The mesophyll leaks calcium oxalate crystals. The minor leaf veins do not present phloem transfer cells and leaks vessels. These plants have stems without secondary thickening and xylem without vessels. The sieve-tube plastids are P-type. The root xylem does not present vessels. These plants are hermaphroditic, with anemophilous or hydrophilous pollination. The flowers are ebracteate, small, and regular. Commonly, the flowers are aggregated

neg: Retrophyllum rospigliosii adaxial sides of the leaves face up on one side of the shoot and down on the other side. The leaf blades are most commonly 10-18 millimeters long and 3-5 millimeters wide. They are ovate-lanceolate or ovate-elliptic in shape with visible midribs and entire margins. Stomata can be found on both surfaces of the leaf. The species is dioecious. The male pollen cones are 5-7 millimeters long with spirally arranged triangular sporophylls. The female seed cones each have a single subterminal fertile cone scale with a single ovule developing into a seed. The seed is covered by a fleshy epimatium.

neg: Abies lasiocarpa commonly found at and immediately below the tree line. It is a medium-sized tree growing to tall, exceptionally to tall, with a trunk up to across, and a very narrow conic crown. The bark on young trees is smooth, gray, and with resin blisters, becoming rough and fissured or scaly on old trees. The leaves are flat and needle-like, long, glaucous green above with a broad stripe of stomata, and two blue-white stomatal bands below; the fresh leaf scars are reddish. They are arranged spirally on the shoot, but with the leaf bases twisted to be arranged to the sides

neg: Brassicaceae be seated or have a leafstalk. The leaf blade is usually simple, entire or dissected, rarely trifoliolate or pinnately compound. A leaf rosette at the base may be present or absent. The leaves along the stem are almost always alternately arranged, rarely apparently opposite. The stomata are of the anisocytic type. The genome size of Brassicaceae compared to that of other Angiosperm families is very small to small (less than 3.425 million base pairs per cell), varying from 150 Mbp in "Arabidopsis thaliana" and "Sphaerocardamum" spp., to 2375 Mbp "Bunias orientalis". The number of homologous chromosome sets varies from four

neg: Nageia toward the ends. Stomata may be found on either both surfaces of the leaf or only the abaxial or underside. The leaf surface is coriaceous. "Nageia" are generally dioecious, with male pollen cones and female seed cones borne on separate individual plants but may sometimes be monoecious. The cones are pedunculate and develop from axillary buds. The pollen cones are long and ovoid-cylindric in shape. They may be solitary or grow in small spicate groups of two to six cones. Each pollen cone has numerous spirally inserted microsporophylls. The microsprophylls may be triangular or apiculate in shape. Each of them

neg: Plant evolutionary developmental biology has been linked to the fall in the atmospheric carbon dioxide concentrations in the late Paleozoic era associated with a rise in density of stomata on leaf surface. This must have allowed for better transpiration rates and gas exchange. Large leaves with less stomata would have gotten heated up in the sun's heat, but an increased stomatal density allowed for a better-cooled leaf, thus making its spread feasible. Various physical and physiological forces like light intensity, humidity, temperature, wind speeds etc. are thought to have influenced evolution of leaf shape and size. It is observed that high trees rarely have

neg: Polytrichum alpinum colonise stony soil, boulders and snowy grikes above the treeline. In Europe, it is often found in arctic and boreal regions, while further south it is restricted to montane landscapes and alpine areas. It is also found in Asia, Africa, the Americas, Australia, New Zealand and Antarctica. In some localities, "Polytrichum alpinum" may be confused with "Pogonatum urnigerum". Key distinguishing features are that the spore capsules of the Alpine moss are at the bottom of large single-celled stomata; the capsule outer wall has smooth cells; the leaf sheath is much longer than that of "Pogonatum urnigerum" and the leaf blade

neg: Banksia novae-zelandiae seam of the middle Gore Lignite Measures. "B. novae-zelandiae" was first published in 2010. The specific epithet refers to New Zealand, where the fossils were found. The fossils are assigned to Banksieae based on several structural grounds, including brachyparacytic stomata, a trichome base architecture unique to Banksieae, "banksioid" venation, and the pinnate leaf lobes. Within Banksieae they are assigned to genus "Banksia" because of their cuticular papillae and the division of the leaves into triangular lobes all the way back to the midrib, neither of which occurs in any other Banksieae genus. (Before the 2007 transfer of "Dryandra" into "Banksia",

neg: Corn grey leaf spot eventually infect new corn crop. In order for the pathogen to actually infect the host, high relative humidity and moisture (dew) on the leaves are necessary for inoculation. Primary inoculation occurs on lower regions of younger leaves, where conidia germinate across leaf surfaces and penetrate through stomata via a flattened hyphal organ, an appressorium. "Cercospora zeae-maydis" is atypical in that its conidia can grow and survive for days before penetration, unlike most spores that need to penetrate within hours to ensure survival. Once infection occurs, the conidia are produced in these lower leaf regions. Assuming favorable weather conditions (see Environment

neg: Banksia novae-zelandiae dispersal of seeds across thousands of kilometers of ocean. Banksia novae-zelandiae Banksia novae-zelandiae is an extinct species of "Banksia", known only from fossil leaves found in the South Island of New Zealand. This species is based on several leaf fossils, all with triangular pinnate lobes cut all the way back to the midrib, and indistinct secondary venation. Stomata occur in areoles, and have very wrinkly subsidiary cells. Both leaf surfaces are covered in trichome bases, and the undersurface is covered in cuticular papillae. Fossil leaves were found at the Newvale Mine, Waimumu Coalfield, Southland District, South Island, New Zealand (),

neg: Leaf In contrast, many other non-seasonal plants, such as palms and conifers, retain their leaves for long periods; "Welwitschia" retains its two main leaves throughout a lifetime that may exceed a thousand years. The leaf-like organs of Bryophytes (e.g., mosses and liverworts), known as phyllids, differ morphologically from the leaves of vascular plants in that they lack vascular tissue, are usually only a single cell thick and have no cuticle stomata or internal system of intercellular spaces. Simple, vascularised leaves (microphylls) first evolved as enations, extensions of the stem, in clubmosses such as "Baragwanathia" during the Silurian period. True leaves or

neg: Stoma a key reactant in photosynthesis, is present in the atmosphere at a concentration of about 400 ppm. Most plants require the stomata to be open during daytime. The air spaces in the leaf are saturated with water vapour, which exits the leaf through the stomata; this is known as transpiration. Therefore, plants cannot gain carbon dioxide without simultaneously losing water vapour. Ordinarily, carbon dioxide is fixed to ribulose-1,5-bisphosphate (RuBP) by the enzyme RuBisCO in mesophyll cells exposed directly to the air spaces inside the leaf. This exacerbates the transpiration problem for two reasons: first, RuBisCo has a relatively low affinity

neg: Nelumbo the area of contact between the water droplet and the leaf. Ultrahydrophobicity is said to confer a very important evolutionary advantage. As an aquatic plant with leaves that rest on the water's surface, the genus "Nelumbo" is characterized by its concentration of stomata on the upper epidermis of its leaves, unlike most other plants which concentrate their stomata on the lower epidermis, underneath the leaf. The collection of water on the upper epidermis, whether that be by rain, mist, or the nearby disturbance of water, is very detrimental to the leaf's ability to perform gas exchange through its stomata. Thus,

neg: Mycosphaerella coffeicola to disperse. A nitrogen-deficient plant as well as a plant with excess nitrogen favors disease prevalence, making well-timed fertilizer applications important. Other factors that can increase disease incidence are insufficient shade, herbicide injury, plant stress, and other diseases caused by nematodes. The reason for increased disease is that stressed plants are more susceptible. Conidia of "Mycosphaerella coffeicola" are produced year-round and enter the coffee plant through stomata on the underside of a leaf, or through the epidermal cuticle on the upper leaf surface. Inter- and intracellular hyphal growth creates vegetative lesions where sporulation occurs. Conidiophores and conidia are formed here,

neg: Mycosphaerella angulata sexual and an asexual stage. The asexual stage of this pathogen was first found in 1902, while the sexual stage was later discovered in 1942. The asexual stage produces conidiophores with conidia, and the sexual stage is an ascus with ascospores - produced by meiosis. Starting with the primary inoculum, the spores get disseminated by the wind. These spores go and infect the leaves by penetration through wounds or stomata penetration. Inter- and intracellular hyphae then infect into the leaf and a conidiophore tuft gets formed on the lower leaf surface. These conidiophore tufts produce conidia which are the second

neg: Black sigatoka emerging through stomata in the streak that has developed. Further epiphytic growth occurs before the re-entry of the hypha into the leaf through another stoma repeats the process. The optimal conditions for "M. fijiensis" as compared with "M. musicola" are a higher temperatures and higher relative humidity, and the whole disease cycle is much faster in "M. fijiensis". Black Sigatoka is also known as Black Leaf Streak, and is found mostly on the banana crop. The pathogen "Mycosphaerella fijiensis" causes streaks that run parallel to the leaves. It is an ascomycete fungus that affects banana trees specifically in tropical climates;

neg: Crassulacean acid metabolism benefit of CAM to the plant is the ability to leave most leaf stomata closed during the day. Plants employing CAM are most common in arid environments, where water comes at a premium. Being able to keep stomata closed during the hottest and driest part of the day reduces the loss of water through evapotranspiration, allowing such plants to grow in environments that would otherwise be far too dry. Plants using only carbon fixation, for example, lose 97% of the water they uptake through the roots to transpiration - a high cost avoided by plants able to employ CAM. The

neg: Melaleuca pomphostoma Bryan Barlow in Nuytsia as a new species. The specific epithet ("pomphostoma") is from the Ancient Greek words "pomphos" meaning "a blister" and "stoma" meaning "mouth" referring to the raised stomata on the lower leaf surface. This melaleuca is confined to the Ravensthorpe district and the eastern end of the Fitzgerald River National Park in the Esperance Plains biogeographic region where it usually grows in sand or clayey loam "Melaleuca pomphostoma" is classified as "not threatened" by the Government of Western Australia Department of Parks and Wildlife. Melaleuca pomphostoma Melaleuca pomphostoma is a plant in the myrtle family, Myrtaceae, and

neg: Ginkgoales unique stomata and isotopic profile give it a key role in recreations of the Mesozoic and Cenozoic. Leaf fossils that resemble the "Ginkgophytes" are known as "Ginkgoites". There are similar, now extinct, morphogens, such as "Sphenobaiera", which describes fan-shaped, deeply divided leaves without clear petioles. The distinctive shape of the modern "Ginkgo biloba" gives the impression of a very narrow leaf morphology, but the group is varied and diverse. The genus "Ginkgo" by itself contains a range of morphologies. "Ginkgo digitata", from the Jurassic, has long, wedge-shaped laminae with the intercostal regions covered in stomata and resin bodies, while "G.

neg: Abies vejarii Abies vejarii Abies vejarii is a species of fir native to northeastern Mexico, in the states of Coahuila and Nuevo León, where it grows at high altitudes (2,000–3,300 m) in the Sierra Madre Oriental. It is a medium-sized evergreen tree growing to 35–40 m tall. The leaves are needle-like, moderately flattened, 1–2.5 cm long and 1.3–2 mm wide by 1 mm thick, grey-green with scattered stomata above, and with two greenish-white bands of stomata below. The tip of the leaf is acutely pointed. The cones are glaucous purple, maturing grey-brown, 6–15 cm long and 4–6 cm broad, with about 150–200

neg: Lenticel stomata, where they can also be affected and destroyed by pressure similar to what can damage to stomatal tissue. Evidently, in both conifers and Lepidodendroids, the parichnoi, as the primary lenticular structure, appear as paired structures on either side of leaf scars. The development and increase in the number of these primitive lenticels were key to providing a system that was open for aeration and gas exchange in these plants. In plant bodies that produce secondary growth, lenticels promote gas exchange of oxygen, carbon dioxide, and water vapor. Lenticel formation usually begins beneath stomatal complexes during primary growth preceding the

neg: Abies alba largest measured tree was 60 m tall and had a trunk diameter of . It occurs at altitudes of (mainly over ), on mountains with rainfall over per year. The leaves are needle-like, flattened, long and wide by thick, glossy dark green above, and with two greenish-white bands of stomata below. The tip of the leaf is usually slightly notched at the tip. The cones are long and broad, with about 150-200 scales, each scale with an exserted bract and two winged seeds; they disintegrate when mature to release the seeds. The wood is white, leading to the species name

neg: Memecylon classification, "Memecylon" was placed in the Memecylaceae. Synapomorphies used in this phylogenetic analysis were anther connective and dehiscence, dorsal glands on stamen connectives, endothecium, placentation, locules, seeds, leaf venation, terminal leaf sclereids, paracytic stomata, stomata shape, leaf sclereids, indumentum, ant and mite domatia, wood and growth form characters, which excluded Memecylaceae from Melastomataceae. However, in "Memecylon" some characters such as seasonal flowering and small size of flowers contributed to the difficulty of assessing relationships based on the morphology. Later, several groups have been either included in broadly defined Memecylaceae or segregated from it. As a result, Memecylaceae comprised the groups

neg: Leaf size absorption of the ground are unfavourable either physically or physiologically. Examples of such structures are: (1) covering of wax, (2) thick cuticle, (3) sub-epidermal protective tissue, (4) water tissue, (5) covering of hairs (6) covering of the stomata, (7) sinking of the stomata, (8) inclusion of the stomata in a space protected from air currents, (9) diminution of the evaporating surface, &c. The matter however is so complicated that it is very difficult to reach an exact appraisal of these adaptations in characterizing the individual plant communities biologically. ... In general we must content ourselves with showing the most frequently

neg: Leaf controlling water loss. Their surfaces are waterproofed by the plant cuticle and gas exchange between the mesophyll cells and the atmosphere is controlled by minute (length and width measured in tens of µm) openings called stomata which open or close to regulate the rate exchange of carbon dioxide, oxygen, and water vapour into and out of the internal intercellular space system. Stomatal opening is controlled by the turgor pressure in a pair of guard cells that surround the stomatal aperture. In any square centimeter of a plant leaf there may be from 1,000 to 100,000 stomata. The shape and structure

neg: Soybean rust hours and moderate temperatures of 60 to 80 °F (15.6 to 26.7 °C). The Process: The infection process starts when urediniospores germinate to produce a single germ tube that grows across the leaf surface, until an appressorium forms. Appressoria form over anticlinal walls or over the center of epidermal cells, but rarely over stomata. Penetration of epidermal cells is by direct penetration through the cuticle by an appressorial peg. When appressoria form over stomata, the hyphae penetrate one of the guard cells rather than entering the leaf through the stomatal opening. This rust and related species are unique in their

neg: Mesophyte system to absorb water; and the ability to develop perennating organs such as corms, rhizomes and bulbs to store food and water for use during drought. Mesophytes do not have any special internal structure. Epidermis is single layered usually with obvious stomata. Opening or closing of stomata is related to water availability. In sufficient supply of water stomata remain open while in limited supply of water stomata are closed to prevent excessive transpiration leading to wilting. Mesophytes generally require a more or less continuous water supply. They usually have larger, thinner leaves compared to xerophytes, sometimes with a greater number

neg: Xerophyte of transpiration is governed by the number of stomata, stomatal aperture i.e. the size of the stoma opening, leaf area (allowing for more stomata), temperature differential, the relative humidity, the presence of wind or air movement, the light intensity, and the presence of a waxy cuticle. It is important to note, that whilst it is vital to keep stomata closed, they have to be opened for gaseous exchange in respiration and photosynthesis. Xerophytic plants may have similar shapes, forms, and structures and look very similar, even if the plants are not very closely related, through a process called convergent evolution.

neg: Strasburgeria rare character. Leaf stems have narrow wings on each side, which is a continuation of the leaf blades. Blades are about 12 cm long and 4–5 cm wide, leathery with a rounded tip, have a foot that gradually narrows into the wings of the leaf stem, and have widely spaced teeth along the margins, particularly in the distal half. These teeth are clear to see in leaves on young shoots but become very subtle on leaves on older growth. The tip of the teeth is opaque. The stomata are restricted to the underside (or abaxial surface), and are of the

neg: Stoma diffusion, and contains carbon dioxide and oxygen, which are used in photosynthesis and respiration, respectively. Oxygen produced as a by-product of photosynthesis diffuses out to the atmosphere through these same openings. Also, water vapor diffuses through the stomata into the atmosphere in a process called transpiration. Stomata are present in the sporophyte generation of all land plant groups except liverworts. In vascular plants the number, size and distribution of stomata varies widely. Dicotyledons usually have more stomata on the lower surface of the leaves than the upper surface. Monocotyledons such as onion, oat and maize may have about the same

neg: Transpiration Transpiration Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost by transpiration and guttation. Leaf surfaces are dotted with pores called stomata, and in most plants they are more numerous on the undersides of the foliage. The stomata are bordered by guard cells and their stomatal accessory cells (together known as stomatal complex) that open and close the pore.

neg: Retrophyllum horizontal plane around the shoot. The leaf petioles in "Retrophyllum" are uniquely twisted on the lateral shoots in opposite directions on each side of a shoot orienting the leaf blades with the adaxial or ventral surface upwards on one side of the shoot and the abaxial or dorsal surface upwards on the opposite side of the shoot. The leaf blade varies in shape from lanceolate to narrowly ovate. The leaves have conspicuous midribs and are amphistomatic with stomata present on both sides. "Retrophyllum" are dioecious with male pollen cones and female seed cones on separate individual trees. The male pollen

neg: Roridula 20–38 μm long and 15–25 μm wide are restricted to the underside of the leaf. Leaf shape, size and shape of the stomata and epidermal cells, the presence of non-glandular hairs, and of stalked glands that strongly differ in size on the lower leaf surface and on the margins including a terminal tentacle, as well as the head of the tentacle having an apical pore, are all characters shared with extant "Roridula" species. These fossils differ from today's dewsticks in having smaller tentacles, and in lacking a prominent midrib on the underside of the leaf. The pieces of amber with

neg: Stoma 1889, was further developed by Metcalfe and Chalk, and later complemented by other authors. It is based on the size, shape and arrangement of the subsidiary cells that surround the two guard cells. They distinguish for dicots: In monocots, several different types of stomata occur such as: In ferns, four different types are distinguished: Stomatal crypts are sunken areas of the leaf epidermis which form a chamber-like structure that contains one or more stomata and sometimes trichomes or accumulations of wax. Stomatal crypts can be an adaption to drought and dry climate conditions when the stomatal crypts are very pronounced.

neg: Bacterial leaf streak bacterial leaf streak will exhibit an orange cast from leaf symptoms and suffer yield and quality loss. Bacterial leaf streak of wheat is a seed-borne disease and is primarily transported by seed, but can also be transmitted by plant-to-plant contact within its lifecycle. Epidemics are typically observed late in the growing season and in wet environments. Moisture facilitates the release of the pathogen from the inoculated seed, which leads to leaf colonization and invasion of tissue. Bacteria on the moist leaf surface enter through leaf openings, such as the stomata or wounds. Under moderately warm weather conditions (15-30 degrees Celsius)

neg: Protosalvinia were produced by meiosis. Because "Protosalvinia" is usually preserved as a compression fossil, it can be difficult to determine whether its anatomy is more like a plant or an alga. Some biochemical evidence favors interpretation as an alga. Lignin and cutin have been found in the thalli, and sporopollenin in the spore walls. The grouping of the spores found in the thallus favors interpretation as a plant. The absence of any stomata on the surface is inconclusive, as all bryophytes lack stomata on the main body of the plant. However, the tips of "Protosalvinia" branches show evidence of conceptacle-like dips.

neg: Cercospora melongenae mycelium protects the next generation of conidia and ensures survival through the winter via conidiophores, and the cycle starts again the next season. "Cercospora melongenae" overwinters in soil or plant debris as conidiophores which then can be dispersed to the plant by rain splash, irrigation water, wind or mechanical transport. The innoculum, conidia, enter through the stomata of the leaves where they germinate and produce more conidia on conidiophores. The conidia must have water or moisture in the form of heavy dew in order to germinate and therefore penetrate the leaf via. the stomata or other natural openings or wounds

neg: Glossary of plant morphology known as stomata, which regulate gas and water exchange. The leaves also possess vascular bundles, which are generally visible as veins, whose patterns are called venation. Leaves tend to have a shorter life span than the stems or branches that bear them, and when they fall, an area at the attachment zone, called the abscission zone leaves a scar on the stem. In the angle (adaxial) between the leaf and the stem, is the axil. Here can be found buds (axillary buds), which are miniature and often dormant branches with their own apical meristem. They are often covered by leaves.

neg: Cherry leaf spot overwinters in dead leaves on the ground. In early spring (about petal fall), fungal fruiting bodies called apothecia develop in these leaves. Spores (ascospores) are produced in the apothecia and are forcibly discharged starting at petal fall. These ascospores are spread by wind or rain to the healthy, new, green leaves and thus serve as the primary inoculum in a new growing season. The ascospores can stick to the leaf and if a film of water and optimal temperature is present, germinate within hours of adhesion. Upon germination, the ascospores can enter the leaf through the stomata (natural openings) on

neg: Bacterial blight of soybean overwinters in crop residue and in seeds. Infection usually begins when the infected plant material is carried by a rainstorm with high winds to healthy soybean plants. Bacteria can enter through natural openings (stomata) or through wounds. In order to enter through natural openings, however, water must be present on the leaf surface. Bacterial Blight may appear after infected seedlings are planted and begin to emerge. In addition to being spread via wind and rain, transmission may occur when leaves of infected soybean rub against leaves of healthy soybean. Symptoms begin to appear 5–7 days after infection. Bacterial blight of

neg: Cephalotaxus fortunei to a point at the end. Their outline is falcate, or sickle-like, to more or less straight and flat. The texture is somewhat leathery, but generally they are quite soft and flexible. The midvein is 0.2 to 0.5 mm wide on the abaxial surface, or underside, showing two broad and grey stomatal bands that are 0.8 to 2.1 mm wide with 13 to 24 rows of stomata, though the individual stomata are not readily visible to the naked eye. The leaf base is cuneate, or wedge-shaped, to shortly attenuate, while the apex is cuspidate, or fine pointed. The cusp, or

neg: Alternaria alternata air currents, and their release from the lesions can be triggered by rainfall, or even just a sudden drop in humidity. When the conidium lands on a leaf, it will wait until the nighttime dew, and then germinate. It can either enter through the stomata, or penetrate directly through the top of the leaf, using its appressorium, infecting the leaf within 12 hours. At the cellular level, toxins are produced by AAL that are essential for pathogenicity on tomato. This host specific mycotoxin is called fumonisin B It was identified and confirmed by research conducted on fast atom bombardment and

neg: Nuphar polysepala that are thick and fleshy. These rhizomes are hard to pry since they are submerged in mud and are difficult to dig. The leaves float on the water surface, and have an external waxy coating which makes the leaf waterproof and thus allows the leaf stomata to breathe freely; they are glossy green, oval, 10–45 cm long and 7–30 cm wide, with a notch at one side to the leaf stem. The leaves provide shelter for fish. The rhizomes (underground stems) are round and submerged in mud. The flowers are 5–10 cm diameter, and have 6 to 12 (most often

neg: Taxonomy of Banksia Salicinae and Spicigerae (that is, all taxa except "B. serrata", "B. aemula" and "B. ornata") and also the western Spicigerae, Quercinae, Grandes, Abietinae and Dryandroideae. The /Cryptostomata were defined as those taxa in which the leaf stomata occur in crypts with constricted entrances. These are usually small shrubs that occur on dry, infertile sandplains. They have beaked follicles and thick, tough, long-lived serrated leaves. It includes all other western taxa, plus the eastern species "B. serrata", "B. aemula" and "B. ornata", and also appears to include "Dryandra". It is worth noting that "Dryandra" does not appear especially closely related to

neg: Hemileia vastatrix µm thick, strongly warted on the convex side, smooth on the straight or concave side, warts frequently longer (3–7 µm) on spore edges. Spermogonia and aecia are unknown. "Hemileia" lifecycle begins with the germination of uredospores through germ pores in the spore. It mainly attacks the leaves and is only rarely found on young stems and fruit. Appressoria are produced, which in turn produce vesicles, from which entry into the substomatal cavity is gained. Within 24–48 hours, infection is completed. After successful infection, the leaf blade is colonized and sporulation will occur through the stomata. One lesion produces 4–6 spore

neg: Osmoregulation of water shortage. Succulent plants such as the cacti store water in the vacuoles of large parenchyma tissues. Other plants have leaf modifications to reduce water loss, such as needle-shaped leaves, sunken stomata, and thick, waxy cuticles as in the pine. The sand-dune marram grass has rolled leaves with stomata on the inner surface. Hydrophytes are plants in water habitats. They mostly grow in water or in wet or damp places. In these plants the water absorption occur through the whole surface of the plant, e.g., the water lily. Halophytes are plants living in marshy areas (close to sea). They

neg: Pachypteris Pachypteris Pachypteris (Brongn.) T.M.Harris. is a Mesozoic pteridosperm leaf fossil probably belonging to the seed fern Order Peltaspermales. "Pachypteris" is represented by hypostomatic, bipinnate or unipinnate leaves, with alethopteridian venation (midvein and secondary veins divided once or twice before reaching the pinnule margin), pinnules with entire margins and rounded apices. The stomata are haplocheilic, monocyclic or dicyclic, usually depressed, with the guard cells occurring in the lowermost part of the stoma. The affinities of "Pachypteris" lay with "Cycadopteris", "Komlopteris", "Dicroidium" (a typical Corystospermalean foliage) and "Ptilozamites". It includes the former denomination "Thinnfeldia" Ettingshausen 1852, a junior synonym of "Pachypteris", as

neg: Cochliobolus victoriae Cochliobolus victoriae Cochliobolus victoriae is a fungal plant pathogen. It caused the disease called "victoria blight" affecting oats and similar grains. "Cochliobolus victoriae" is a fungus that causes Victoria blight in oats. Symptoms include stem weakening, seedling death, leaf damage, and premature ripening of seeds. Other symptoms include basal necrosis and foliar striping, which begins at the lower leaves and proceeds upwards. Blackened nodes and root rot can also be symptoms. Conidiophores emerge from the stomata or epidermal cells of the diseased oat, usually in groups of two to five, and are a medium-brown color. Victorian oat varieties have resistance

neg: Perittia lonicerae Perittia lonicerae Perittia lonicerae, the honeysuckle leaf miner, is a moth of the family Elachistidae. It was first discovered in Hawaii in 1949. It was later found in Japan in 1982, although it was described as new. Several other species are known from the eastern Palearctic Region, so it is likely that "P. lonicerae" originated there instead of Hawaii where it was first found. The larvae feed on "Lonicera japonica". They mine the leaves of their host plant. There is usually only one mine per leaf, but occasionally two mines will be found in a single leaf. The mine starts

neg: Exobasidium vexans lesions. These lesions give the lower surface of the leaf the characteristic blister like appearance. Spores are wind dispersed and readily germinate, usually within 24 hours. "E. vexans" can enter the host plant via the stomata or direct penetration with an appressoria and growth proliferates intracellularly. "E. vexans" is the most economically significant tea pathogen in many countries, causing up to 50% crop yield loss when uncontrolled. (Mur et al. 2015, Ajay et al. 2009) Tea Blister Blight infection affects the production of multiple metabolites within the plant, including the reduction of alkaloid caffeine, which has a key role in

neg: Pachypteris the Russian Federation Antarctica, Argentina, Australia, Colombia (Valle Alto Formation, Caldas), France, Georgia, India, Iran, Italy, Japan, Lithuania, Norway, Poland, Romania, the Russian Federation, Serbia and Montenegro, Tajikistan, the United Kingdom, and Uzbekistan. Argentina Pachypteris Pachypteris (Brongn.) T.M.Harris. is a Mesozoic pteridosperm leaf fossil probably belonging to the seed fern Order Peltaspermales. "Pachypteris" is represented by hypostomatic, bipinnate or unipinnate leaves, with alethopteridian venation (midvein and secondary veins divided once or twice before reaching the pinnule margin), pinnules with entire margins and rounded apices. The stomata are haplocheilic, monocyclic or dicyclic, usually depressed, with the guard cells occurring in the

neg: Phoma clematidina in plant debris and soil during unfavourable conditions. Many publications report "Phoma clematidina" to be a wound pathogen. However, although wounding may aid infection, scientific trials have shown that, in susceptible "Clematis" varieties, the fungus can cause extensive leaf spotting and wilt without any previous damage to plant tissues. When spores of "Phoma clematidina" land on a leaf of a susceptible plant under the right environmental conditions (moisture, temperature 15 to 25 °C), they will germinate within 6 hours and infect leaf tissues directly or via leaf hairs (but never via stomata). Initial symptoms are small brown lesions which then

neg: Roridula and a thick, hoof-shaped or egg-shaped head, with a small pore at its very tip. The stalks are 20–350 μm long (one stalk reaching 1.4 mm), the heads 20–120 μm long and 10–40 μm wide. Organic remains and hairs of other plant species are positioned on the heads, suggesting these were sticking to a secretion from the heads. The surface of the leaf consists of small six-sided cells at the base of the leaf and long, larger cells from the center to the tip of the leaf. These epidermal cells are 3–54 μm long and 6–18 μm wide. Stomata of

neg: Evolutionary history of plants after the simple leafless plants had colonized the land in the Early Devonian. This spread has been linked to the fall in the atmospheric carbon dioxide concentrations in the Late Paleozoic era associated with a rise in density of stomata on leaf surface. This would have resulted in greater transpiration rates and gas exchange, but especially at high concentrations, large leaves with fewer stomata would have heated to lethal temperatures in full sunlight. Increasing the stomatal density allowed for a better-cooled leaf, thus making its spread feasible, but increased CO2 uptake at the expense of decreased water use efficiency. The

neg: Epidermis (botany) asymmetrically to form the subsidiary cells. Because stomata play such an important role in the plants survival, collecting information on their differentiation is difficult by the traditional means of genetic manipulation, as stomatal mutants tend to be unable to survive. Thus the control of the process is not well understood. Some genes have been identified. "TMM" is thought to control the timing of stomatal initiation specification and "FLP" is thought to be involved in preventing further division of the guard cells once they are formed. Environmental conditions affect the development of stomata, in particular their density on the leaf surface.

neg: Citrus canker susceptible hosts. The bacteria infect new plants through stomata and wounds. The wound can be caused by pruning or hedging that could cut open mesophyll tissues for direct infection. The rain can also cause water congestion on leaf surface, form column of water through stomata and promote infection through the natural opening. The infection can form on fruit, foliage and young stem. Leaves and stems are most susceptible to infection within the first six weeks of initial growth. Infection of fruit is most likely to occur during the 90 day period after petal fall during fruit formation. The varied size

neg: Gas exchange roles of carbon dioxide, oxygen and water vapor. is the only carbon source for autotrophic growth by photosynthesis, and when a plant is actively photosynthesising in the light, it will be taking up carbon dioxide, and losing water vapor and oxygen. At night, plants respire, and gas exchange partly reverses: water vapor is still lost (but to a smaller extent), but oxygen is now taken up and carbon dioxide released. Plant gas exchange occurs mostly through the leaves. Gases diffuse into and out of the intercellular spaces within the leaf through pores called stomata, which are typically found on the

neg: Abies nordmanniana more than 400–500 km. It is a large evergreen coniferous tree growing to 55–61 m tall and with a trunk diameter of up to 2 m. In the Western Caucasus Reserve, some specimens have been reported to be and even tall, the tallest trees in the Caucasus, Anatolia, the Russian Federation and the continent of Europe. The leaves are needle-like, flattened, 1.8–3.5 cm long and 2 mm wide by 0.5 mm thick, glossy dark green above, and with two blue-white bands of stomata below. The tip of the leaf is usually blunt, often slightly notched at the tip, but can

neg: Urban forest are shaded in parking lots, evaporative emissions from fuel and volatilized plastics will be greatly reduced. The volatile components of asphalt pavement evaporate more slowly in shaded parking lots and streets. The shade not only reduces emissions, but reduces shrinking and cracking so that maintenance intervals can be lengthened. Less maintenance means less hot asphalt (fumes) and less heavy equipment (exhaust). The same principle applies to asphalt-based roofing. Trees also reduce pollution by actively removing it from the atmosphere. Leaf stomata, the pores on the leaf surface, take in polluting gases which are then absorbed by water inside the leaf.

neg: Simarouba amara being able to escape diseases. Plant physiologists have investigated how the leaves of the tree differ depending on their location in the forest canopy finding they are thicker in the canopy and thinner in the understory. They have also measured how the water potential of their leaves changes and when their stomata open and close during the day; the findings suggest that rather than closing their stomata to control water loss, it is controlled by the leaf area instead. Population geneticists have examined the way in which its genes vary, at both the local scale and across its range using

neg: Biological Dynamics of Forest Fragments Project below wilting point occurred in the forest during dry season, but the driest points were not necessarily near the edge and no evidence of prolonged drought was found. Thus, any edge drought effects on plants must be due to combined effects of reduced soil moisture and higher atmospheric demand exceeding the supplying power of vascular systems, rather ecosystem-level water shortage. Plant responses: For leaf expansion in "Duguetia", there was no difference in the rate of leaf expansion between plants in edge zones and those in control areas. When looking at whether canopy trees close their stomata to reduce water loss

neg: Photorespiration increased by: Factors which influence this include the atmospheric abundance of the two gases, the supply of the gases to the site of fixation (i.e. in land plants: whether the stomata are open or closed), the length of the liquid phase (how far these gases have to diffuse through water in order to reach the reaction site). For example, when the stomata are closed to prevent water loss during drought: this limits the supply, while production within the leaf will continue. In algae (and plants which photosynthesise underwater); gases have to diffuse significant distances through water, which results in a

neg: Burton's legless lizard its distribution. It is usually found in low vegetation or debris on the ground such as leaf litter which has been shown to be important to specimens located in tropical environments. This was demonstrated in an experiment where individuals were given a choice of several thermally comparable environments and there was an overwhelming preference for leaf litter by specimens from the tropics. In areas where leaf litter is not as readily available this species will use grasses, abandoned burrows and other shelter that it can find as habitat. "L. burtonis" feeds almost exclusively on lizards. Generally, skinks are the main

neg: Abies grandis in the Pacific Northwest. "Abies grandis" is a large evergreen coniferous tree growing to 40–70 m (exceptionally 100 m) tall and with a trunk diameter of up to 2 m. The leaves are needle-like, flattened, 3–6 cm long and 2 mm wide by 0.5 mm thick, glossy dark green above, and with two green-white bands of stomata below, and slightly notched at the tip. The leaf arrangement is spiral on the shoot, but with each leaf variably twisted at the base so they all lie in two more-or-less flat ranks on either side of the shoot. On the lower leaf

neg: Photosynthesis system concentration increases. This is less tolerant to leakage and material ad/absorption. For CO to diffuse into the leaf, stomata must be open, which permits the outward diffusion of water vapour. Therefore, the conductance of stomata influences both photosynthetic rate (A) and transpiration (E), and the usefulness of measuring A is enhanced by the simultaneous measurement of E. The internal concentration (C) is also quantified, since C represents an indicator of the availability of the primary substrate (CO) for A. A carbon assimilation is determined by measuring the rate at which the leaf assimilates . The change in is calculated as

neg: Chinese leaf warbler is dark brown. The Chinese leaf warbler can be found in confined regions or locations in central and north-eastern China. It is common in Xin Shui, Sichuan Province. The species is migratory, but its wintering grounds are currently unknown. It inhabits mountainous forests, preferring spruce and fir. It can be found at elevations of 200–2800 m, but usually between 1000 m and 2600 m. This species favors low secondary growth. Chinese leaf warblers can be found singly or in pairs during the breeding season. These birds are generally somewhat bold in personality. They almost always keep to tree canopies, where

neg: Mycosphaerella musicola about five days before penetrating the leaf via a stoma. Once inside the leaf the invasive hypha forms a vesicle and fine hyphae grow through the mesophyll layers into an air chamber. More hyphae then grow into the palisade tissue and continue on into other air chambers, eventually emerging through stomata in the streak that has developed. Further epiphytic growth occurs before the re-entry of the hypha into the leaf through another stoma repeats the process. Both conidia and ascospores are important for dispersal of M. musicola with the ascospores being involved in the movement of the pathogen over longer

neg: Primary production by the processes of photosynthesis (see above) and transpiration. The latter process (which is responsible for about 90% of water use) is driven by the evaporation of water from the leaves of plants. Transpiration allows plants to transport water and mineral nutrients from the soil to growth regions, and also cools the plant. Diffusion of water vapour out of a leaf, the force that drives transpiration, is regulated by structures known as stomata. These structure also regulate the diffusion of carbon dioxide from the atmosphere into the leaf, such that decreasing water loss (by partially closing stomata) also decreases carbon

neg: Gas exchange lower surface of the leaf. Gases enter into the photosynthetic tissue of the leaf through dissolution onto the moist surface of the palisade and spongy mesophyll cells. The spongy mesophyll cells are loosely packed, allowing for an increased surface area, and subsequently an increased rate of gas-exchange. Uptake of carbon dioxide necessarily results in some loss of water vapor, because both molecules enter and leave by the same stomata, so plants experience a gas exchange dilemma: gaining enough without losing too much water. Therefore, water loss from other parts of the leaf is minimised by the waxy cuticle on the

neg: Xanthomonas campestris pv. campestris cotyledons may develop blackened margins, shrivel, and drop. The bacteria progress through the vascular system to the young stems and leaves, where the disease manifests as V-shaped chlorotic to necrotic lesions extending from the leaf margins. Under humid conditions, bacteria present in guttation droplets can be spread by wind, rain, water splashes, and mechanical equipment to neighboring plants. The natural route of invasion by Xcc is through the hydathodes, though leaf wounds caused by insects and plant roots may also be portals of entry. Occasionally, infections occur through stomata. Hydathodes provide the pathogen a direct path from the leaf margins

neg: Cherry leaf spot the underside of the leaf. Ascospores cannot enter immature stomata very effectively. These ascospores grow in the intercellular spaces in the leaf. Incubation time will vary depending on the amount of available moisture and temperatures. The small purple lesions can appear within 5 days if there are damp conditions and the temperature remains steady between . This incubation period could take as long as 15 days though if lower temperatures and drier conditions occur. Generally leaves become less susceptible to the disease as they grow older during the course of the growing season. The first sign of disease may be

neg: Pinophyta opposite pairs or whorls of 3 (−4). In many species with spirally arranged leaves, such as "Abies grandis" (pictured), the leaf bases are twisted to present the leaves in a very flat plane for maximum light capture. Leaf size varies from 2 mm in many scale-leaved species, up to 400 mm long in the needles of some pines (e.g. Apache Pine, "Pinus engelmannii"). The stomata are in lines or patches on the leaves, and can be closed when it is very dry or cold. The leaves are often dark green in colour, which may help absorb a maximum of energy

neg: Melaleuca pomphostoma to 12 individual flowers, the spike about wide. They are greenish-yellow with the stamens arranged in five bundles around each flower, the bundles containing 11 to 18 stamens. The flowering season is in autumn and winter and is followed by fruit which are woody capsules long. "Melaleuca pomphostoma" is similar to "Melaleuca bracteosa" but differs from it in having fewer stamens ("M. bracteosa" has 7 to 11 per bundle), a different leaf shape and distinctive, numerous, white raised stomata, which are barely visible with a hand lens, on the leaf blades. "Melaleuca pomphostoma" was first formally described in 1992 by