The main part of the leaf blade is usually flat, a very thin, in favor of light
The photosynthesis of leaf tissue penetration and absorption of light, the largest area of carbon dioxide.
blade Plant leaves
blade Leaf characteristics
The blade has a top surface and a lower surface (ventral) (back) points. Both sides of some plant leaves or only in the back with a variety of hair, such as pilose, Hair
Hard, hair, bristle, scaly hairs, or branched to four radiation stellate hairs. Yes, we have Leaf blade abaxially
Covered with a layer of white powder, some in Abaxial surface densely glandular.
There are leaves of many plants glabrous, without any appendages.
Most of the internal leaf Tissue differentiation
A rich in chlorophyll Parenchyma
The leaf is green. The distribution between the leaf parenchyma vascular bundle
, known as the vein. Leaf blade plays a supporting role to stretch and transporting.
blade Blade blade
Lamina, limb, leaf by blade Epidermis
The main part and vein of leaves. The foliar surface has a layer of tightly packed cells, respectively The upper epidermis
And the lower epidermis. The epidermis consists of only one layer of cells.
Schematic diagram of the structure of the blade
Leaf morphology and function with plant species and there are different, but generally is from Leaf primordium
Flat structure and the upper part of the development, contains a large number of Chloroplast
To vigorously carry out photosynthesis. The epidermis is divided into The upper epidermis
And under the skin, usually because of the nature of the upper and lower sides of different forms of dorsal ventral, also some leaves were cylindrical, no difference on both sides. To the vein (vein and leaf tip (lines) Tip
), edge (leaf margin) and stem (Ye Jing) is one of the important characters of morphological difference between plant species.
blade Leaf development
If the leaf margin parted significant main veins, leaf will split into several leaflets. The morphology and differentiation of leaf veins form, even in the same plants are not the same. According to the can see some changes in the stem position. General support from the petiole on stems, but there are also many leaves by itself directly from stems. Sessile leaf
. To a certain size in leaf primordia branches occur, tip top cell growth, leaf margin of cells Marginal growth
, and the formation of leaves. But in the process of leaf growth, from meristem
The cells produced more repeated division, elongation and increase final maturity for fixed Leaf
. This leaves Intercalary growth
(intercalary growth of leaf) with plant species and there is a significant difference, usually Epidermis
At the same time as the internal organization of layer growth, the outside is still complex in the leaves, mesophyll
In general the abaxial surface of several layers of cells showed a precocious tendency in the adaxial side no one to several layers of cells as strong separatist activities of the division, formation of free cell gap in this part between cells. Each cell that the abaxial side of is stretched and differentiated into Sponge tissue
. On the other hand, the adaxial surface of one or more layers of cells continue to split lengthwise, through cell differentiation
A Palisade tissue
. In the development process of leaf veins. Procambium
At the same time differentiate into many small veins, in addition, in many cases, abaxial epidermal cells are differentiated into holes. The blade surface is a mature Cuticle
In young leaves, buds, many cases are complex stem tip of the state, but when the buds and leaves start active growth period, leaf was flat. Leaves due to limited growth, so the mature setting will no longer continue to grow and deformation, but in Fern
The top leaves, or extended racemose, or produce adventitious buds; in Seed plant
Such as the use of. Auxin
The leaves can also induce rooting and elongation.
blade Leaf morphology
blade brief introduction
The leaf morphology including the entire leaf shape, leaf tip, leaf base, leaf edge parts etc..
blade Leaf shape
Refers to the two leaf blade shape. Different plants, leaves vary greatly, even in different plants of the same plant, or the same plant of different branches, leaf is not absolutely the same, how many there will be some changes, but does not mean that the same leaf of a plant is the change of it with countless changes, or in a certain within the scope of.
The top leaves slender, tapering like needle, semicircular cross section, such as pine; cross section is triangular, such as cedar.
(2) lanceolate leaf length is about 4~5 times the width, below the middle of the most wide, attenuate upward, such as Weeping willow
If the above middle; the most wide, tapering downward, to oblanceolate, such as bayberry.
(3) moment round or oblong. The leaf length is about 3~4 times wide, on both sides of the edge slightly parallel, such as Ilex cornuta
(4) the oval leaf length is about 3~4 times the width of the most wide in the middle of blade, on both sides of the edge of the curved ends, equal circle, such as osmanthus.
(5) oval leaves length is about 2 times as wide or less, the most wide in the middle of the following, to gradually narrow, such as Privet
If the above middle; most wide, tapering down to obovate, such as. Pittosporum tobira
(6) circular leaf length and width nearly equal, shaped like a disk, such as kiwi.
(7) leaves a long and narrow strip, 5 times as long as wide, on both sides of the edge nearly parallel, such as metasequoia.
(8) the upper spatulate narrow leaves, wide and round, tapering down like a spoon, such as Calendula officinalis
At the top of the blade are very wide and slightly rounded, tapering downward, a plicate opening, such as ginkgo biloba.
(10) the sickle shaped leaves are narrow and less curved, sickle, like taxus chinensis var.mairei
(11) end of the outer convex kidney shaped blades at both ends, the other end is concave on both sides of the blunt, like the kidneys, such as wishful pansy.
(12) the heart-shaped leaf length and width for example but ovate, base width and round, and concave, such as Bauhinia; such as wide at the top round and recessed for obcordiform, such as Creeping oxalis
(13) pandurate like leaves ovate or elliptic, concave on both sides obviously, such as St
Leaves nearly equilateral rhomboid, such as tallow.
(15) triangle leaf base truncate wide, on both sides to the top is a collection of any three edges near equal form, such as Polygonum perfoliatum
(16) squanous refers to small leaves was leaf scales, such as Platycladus orientalis
. These are some of the more common form, besides this, sword shaped, wedge shaped, arrow shaped etc..
In fact, in a variety of plants, leaf is far more than these, is not entirely like the so typical, for example it is like like ovate, lanceolate, it can only be called ovate lanceolate; sometimes it is like like oblanceolate, spatulate, oblanceolate to call it spoon. In the observation of leaf shape, some plants have to pay attention to Heterophyllous
The characteristic is on the same plant, has two obvious inconsistent leaf. as Ficus pumila
No, in flowering branches, leaves small and thin, ovate in heart; flowering branches, leaves a large thick leathery, ovate elliptic, both the size of several times, but the two leaf can appear in the same plant. Aquatic plant
Ling also so, leaves Chengling triangle shaped floating on the water, sink in water leaves for feather fine crack, differences between the two. Heteromorphic leaves appear in different plants of the same type, more trouble, such as Zhe tree
The male and female plants were not a leaf, often mistaken for two kinds of plants.
Refers to the end of the blade tip away from the stem, also known as the top, top, top. There is a common:
(1) the top leaf tendril shaped into a spiral shaped or zigzag appendages.
(2) awn tip top leaves suddenly turned into a different length of hard and straight shaped drill tip.
(3) the top leaves caudate tapers, is long and thin, like the tail of an animal.
(4) acuminate leaf tip tip extension, with both sides of the bend.
(5) a sharp blade tip Acute angle
Shaped, hard and sharp tip, on both sides of the straight edge.
(6) cuspidate leaf tip gradually turned into a hard and long pointed, shaped like a bird.
(7) blunt leaf tip obtuse or narrowly rounded.
(8) the convex tip blade tip extending outward from the midrib, forming a short and sharp tip.
(9) convex blade tip extending outward from the midrib, forming a short convex head.
(10) micro concave blade tip into the central head, slightly sunken, the formation of circular notch.
(11) concave blade top and form a broad range of gap.
(12) obcordiform on both sides of top notch curving blade.
In addition, there are convex, truncate, thorn fracture and so on.
blade Leaf base Leaf base
One end is refers to the leaves near the stem base, also known as the lower. Common are the following:
(1) the heart-shaped base connected recessed in the petiole into a notch, on both sides of the formation of a circular edge.
(2) the earlobe shaped base has two lobes shaped small lobes.
(3) arrow base on each side of a backward and outward slightly small lobes, lobes usually sharp.
(4) wedge blade below the middle of both sides of the base to gradually narrow, shaped like a wedge.
(5) hastate base on each side of the outwardly extending lobes, lobes usually sharp.
(6) peltate leaf and petiole leaf are connected in the central, or at the edge of less than one point.
(7) oblique base on both sides of the uneven size.
(8) wear stem base deep concave on both sides, and surrounded by the lobes matched stem, stem like leaves throughout.
(9) hold the stem has no petiole leaf, the both sides of the base hold stem.
(10) with wear stem base on two lobes leaves each other forming a whole, but the stem like throughout the leaves.
(11) truncate basally truncate in a straight line, as if cut.
(12) two base tapering gradually become narrow incurved, tip acuminate and similar.
blade Leaf margin
That leaves except leaf margin, leaf base edge tip. Common are the following.
(1) entire leaf margin intact, into a smooth line.
(2) toothed leaf margin with sharp teeth, but both sides of the teeth subequal, tip directed outward.
(3) serrated leaf margin, sharp corners are notched, flat on both sides of the notch of the tooth tip, and forward. Such as Nick small, called small toothed; such as tooth tip glands, called glandular serrate.
(4) on both sides of double serrate leaf margin on teeth and small teeth.
(5) leaf margin crenate with circular arc shaped protrusion of the notch, two arc connected to form a concave angle.
(6) concave dentate leaf margin inward arc notch depression, two sharp arc connected to form a convex.
Shun edge wave, such as ups and downs, corners are blunt shaped.
(8) eyelash shaped leaf margin with fine wool out.
(9) palmately lobed leaves palmately veined, palmately arranged between the lobes along veins, lobes depth of not more than 1/2.
(10) palmatipartite lobes arrangement above, lobes depth is more than 1/2, but not for discontinuous notched leaves.
(11) palmatisect lobes arrangement as above, the central deep lobes, causing leaf discontinuity between lobes separated from each other.
(12) pinnately lobed leaves with pinnate lobes, midrib sides like feathery lobes split, depth of not more than 1/2.
(13) pinnatipartite lobes arrangement above, lobes with depth palmatipartite.
(14) 2-pinnatisect lobes arrangement above, lobes with depth palmatisect. In the identification of plants, in leaf shape, leaf margin, leaf tip, Ye Ji the four, should focus more on leaf margin, leaf margin as compared with the other three, particularly the stability of its characters. as Dalbergia
Entire leaflets, White oak
Leaf margin undulate, cyclobalanopsis glauca
Leaf margin serrate above 1/2, Incense
Leaflet margin double serrate and so on, are extremely stable. Of course, is not to say that the leaf margin in the form of immutable and frozen within one species, a few plants, especially in the Cultivated plants
There will be some changes. Such as osmanthus leaf margin sharply serrate leaf margin, but some plants are almost entire; Myrica rubra leaf margin is entire, but sometimes serrate, a similar situation in general is rare. In contrast, leaf shape variation is more, in the same kind of different plants, even in different branches of the same plant, the leaf will also have a lot of changes, there is a big gap between. Such as vertical leaf shape, lanceolate oblong, obovate or obovate oblong, broadly elliptic and etc.. The same plant, with two or three kinds of leaf is very common, especially in the initiation of leaf branch and leaf growth, normal branches tend to vary greatly.
blade Fan blade Fan blade
Is the wind turbine components. Wing type for each section on the design, from root to leaf tip, the thickness and twist angle of chord length distribution is good, The air force
The impeller generally consists of three parts of blade, front and back cover, wheel hub. Blade runner liquid in the impeller. The impeller is fixed on the shaft by rotating with the key, and the shaft of the motor, energy transfer to the liquid, the liquid energy. The impeller is closed, open and semi open three types. According to the inhalation method: single suction and double suction impeller.
The centrifugal pump blade according to the different export angle may be divided into blade, radial blade and blade. The use of centrifugal pump blade.