Structure of the flower
Essence about the colored structure, more unanimous view inclines to regard the flower as abnormal short one shortenned among one festival, every part of the flower has general nature of the leaf according to shape , structure. It was poet , dramatist and naturalist of Germany Goethe (Goethe 1749-1832 ) that proposed this view at first, he thinks the flower is abnormal one that is suited to breeding function . This view has got the support of the fossil record and much systematic development and ontogeny evidence, and can explain the structure of most angiosperm flowers well , therefore continue to use so far.
An intact flower includes six basic parts, namely the pedicel (pedicel), receptacle (receptacle ) , calyx (calyx ) , corolla (corolla ) , the stamen group (androecium ) and pistil group (gynoecium ). Among them the pedicel and receptacle are equivalent to the part of one, four other parts are equivalent to the abnormal leaf on one, Chang He is called the flower department (flower parts ). An four available flowers are called the complete flower (complete flower ), the ones that lacks among them let a part call the imperfect flower (incomplete flower ).
Every part (such as calyx , corolla , stamen group and pistil group ,etc. ) and inflorescence of the flower are in the course of long-term evolution, have produced the adaptability variation of all kinds, therefore has formed various types.
Shape in different poses and with different expressions form that structure spend, among about 250,000 kinds of angiosperm, there is 250,000 kinds of colored styles. But it is diagrammatic that all flowers still have common structure, their composition is usually:
The part that the receptacle flower connects with stem , made up among festival and festival, the ones that grew the flower be able to be bred with sterile attached objects on festival. These section often because shortening and suppressing closely crowded and together among the festival, causing receptacles remarkably and out of shape, so, are not all very like stems on the form , size and structure. The receptacle is had sterile some (husks , sepals , petals ) grown but spiral ground or a round of dried rhizome of rehmannia is arranged together closely. While verticillating and arranging , between upper and lower wheels , often become alternative permutation. Some the same class organs of plant, can form two or many wheels such as the petal (heavy flowers), such as the heavy green peach blossom of one.
The calyx is outside the most of the flower, other parts to the flower shield. Can divide several sepal into , similar to the leaf or husks very much on constructing in form. The green sepal contains chloroplasts, have air vent (device ) and epidermis mao on the epidermis storey, but seldom split up and go out of the bar to organize and organize with the sponge like leaf. In morphology , regard the calyx as a kind of leaf out of shape. The sepal generally becomes a form to arrange , but some primitive departments, for example Mao GenKe arranges for the spiral . They can become the form of the petal , or combine with petal degradating. The sepal is extreme while degradating, become thin tooth , scale , sting the hair or becoming small and protruding. After being fertilized, the calyx comes off or the constellation exists , the calyx that the constellation stores has important protective action on the development of the fruit.
The corolla is within the calyx, the corolla can usually be split into the slice, is called the petal. The petal is generally bigger than the sepal, think in morphology the petal is a sexual organ of a kind of leaf too. Calyx and corolla is it spend quilt to claim jointly. Epidermis layer of petal go to , can have air vents and epidermis mao. Great changes have taken place for the size and form of the petal. Some are very old, some are quite tiny , even degradate into a scale , sting hair or various kinds of glands body. Corolla except having protective action, color and fragrant smell of the petal, have an important effect on attracting animals and pollinating. The corolla has various kinds of bright colors, because contain the pigment in coloured body and cell's liquid in the cell, influence that while receiving cells , various kinds of factors outside change. Some flower of anemophilous flower very obvious, green or almost colourless.
Separate joint situation , underpart of the corolla and size shutting and becoming corolla tube according to the petal, such characteristics as the form and depth of and the lobe of a leaf of corolla ,etc., can divide the type of the corolla into : Tube-shape (the tubular flower of the sunflower), form of the funnel (sweet potato ) , the clock form (the root of balloonflower ) , a form (tomato ) , lip shape (sesame ) , tongue form (the ligulate flower of the sunflower ) , butterfly's shape (peanut ) and cross Among them because of tube-shape, form of the funnel , the form of the clock, a form and cross corolla, petal its form and size more unanimous, so this kind is spent symmetrically for radiation. And lip shape , tongue form and butterfly shape corolla, its petal form , size are inconsistent, present bilateral symmetry. There are flowers too, if the flower of the canna is asymmetric.
General name of all stamens of a flower of stamen group. In all kinds of plants, the figure of the stamen and shape characteristic are comparatively steady, can often make the basis classified and determining for the plant . Generally more primitive plant of each, there is a lot of figure of stamens, become several side by side ; Each that relatively evolved, figure reduces, invariable, or count with the petal together, or several is times as much as that of the petal counts . In one flower, if have 4 stamen, among them two filigree relatively long, two are relatively short, call two strong stamens, such as the lip shape department and subject plant of root of Zhejiang figwort; And for example there are 6 stamens of a flower, 4 2 long short ones among them, call the top four stamens, such as the Cruciferae plant. In addition, the filigree or anther part in the stamen, often have and connect with the phenomenon, if the anther is totally separated , and the filigree is united into one bunch, call the single stamen, for instance hollyhock , cotton ,etc.; The filigree connects in parallel and becomes two bunches, call two body stamens, for instance broad bean , pea ,etc.; The filigree is shut as 3 bunches, call three body stamens, such as the forsythia; Shut it for the title many body stamen of more than 4 bunches, for instance gold silk peach and castor plant,etc.. On the contrary, the filigree is totally separated , and the anther unites each other, call and gather the medicine stamen, such as the composite family, calabash subject plant.
Every stamen,it is usually it is from anther and catch it make up in pieces of detailed filigree of it. Whether anther catch way can divide into in filigree. The whole medicine, anther was all born in on filigrees , such as the lotus; Base medicine, only the anther base department was born in the filigree top, such as the nutgrass flatsedge , small bark of a cork tree; Carrying medicines, the back of the anther was born in the filigree top, such as the tung oil tree; T medicine, some was born in the filigree top in the middle of the anther back, easy to wave, such as the wheat, rice; Wide fork medicine, the medicine room is totally separated into a straight line, born in the filigree top, such as the digitalis; The word medicine of " one ", the base department of medicine room opened, was born in on the top of filigrees above.
Usually each anther is made up by two medicine ones, medicine one of each one has two pollen bags , medicine room where among them there are anther walls and the small spore emerges (spore ascus). On the later stage when anther get wall development,it is can from epidermis layer , medicine room inboard wall, in layer and fine hair felt layer ,etc. cell of 4 layers make up (among ). Having master cells of a lot of small spores of each spore ascus, they are each after meiosis , produce the small spores of four monoploids . Each small spore (core ) was split once again after this, formed a big nutrition cell (or called and was in charge of cores), with a little reproduction cell (core), pollen one (namely male gametophyte ) is ripe basically to have two cells at this moment. Before the ripe anther fractures, separating between the medicine rooms may already break , the anther of four spores ascus is turned into two pollen bags promptly. One is released out from the anther fracturing promptly in the pollen. The way is as follows, that the anther fractures Splitting vertically, fracture along the intersection columns of two pollen bags , for instance the rape, morning glory,etc.; Splitting sideways, split open horizontally in the middle part of the anther, for instance wooden Jin , hollyhock ,etc.; The hole splits, have aperture form breach on the anther top , for instance eggplant , tomato ,etc.; One splits, the anther side wall is fractured into several, for instance the camphor tree, small bark of a cork tree,etc..
General name of all pistils of a flower of pistil group. The pistil lies in the centre of the flower, is grown the carpel of one of embryo to make up . It is generally acknowledged carpel to make up base unit of pistil , one flower have skin or a lot of carpels make up for the pistil group wholeheartedly. Carpel leaf abnormal. A roll of , a piece of suture meeting to take shape partly of heart suitcase, call the belly suture, a relative one namely carpel hit rib office for carry suture.
The pistil formed by one or a lot of carpels, the part which the base department can breed , expand that often split up , called the ovary, and the sterile part on the ovary, namely the style and column cap . Grow the difference of situations on the flower according to the ovary, divided into: Go to the seat room - -The ovary bottom link with receptacle, these kind of flower calls the next flower. Such as Mao Gen and peach of gold silk; Put the seat room - -Sink into the receptacle under the whole ovary, and totally heal with the receptacle, this kind of flower is called and gone to the location flower, such as the pumpkin; There are seat rooms of half times - -The downing a half of the ovary heals with the receptacle, this kind of flower is called the location flower for week, for instance beet ,etc.. The receptacle of the location flower is expanded into the form of the cup or pot form more or less in week, the ovary is grown in the central authorities, flower and stamen enclose seat room ovary still not going to,such as peach blossom, so on the week can have not for seat room or half an of seat rooming spending location . In addition, according to making up the figure of carpel of the pistil and combining the way differently, two big classes that can divide the pistil into the single pistil and reply pistils . The single pistil is also called before growing the carpel pistil, the pistil that a flower and only one carpel among them formed , for instance soybeans, peach ,etc.; There is single pistil that a flower is separated each other by the majority too, whose name is for instance Mao Gen , strawberry ,etc.. Reply pistils and also call and grow the carpel pistil jointly , is jointly taken shape by two or more carpels, ovary HeSheng among them, the style separates from column cap , for instance the castor plant, China pink,etc.; Ovary and style are grown jointly, but the column cap is separated , such as the cotton , sunflower; Have ovary , style , 3 column cap person born jointly all too, for instance rape , citrus ,etc.. By the look of view that the system is developmental, the single pistil is a more primitive type.
The column cap lies on the style, its surface is coarse and has mucus, this is the place where accept pollen. Grow one or several ovules in the ovary. The place to grow of ovule, is called the placenta. The placenta is often divided into: Edge placenta, room one of single carpel , ovary, the ovule is grown and sewn on the line in the belly of the carpel, such as the beans; Side membrane placenta, the ovary formed by two or more carpels, the ovule was born in the edge of the carpel such as the rape , cucumber; Pivot placenta, formed the ovary of many rooms by the suspicious peel, the ovule was born in the pivot part of the ovary, such as the cotton , citrus; Specially setting up the central placenta, formed the ovaries of room one by the suspicious peel, the ovule is grown on the pivot separated from ovary wall, such as the pinkwort; The base grew the placenta, the ovule was born in the department of sub foundations, such as the composite family plant; Carried and grew the placenta, the ovule was born in the top of the ovary, such as the subject plant of winter daphne. Ovule from pearl and pearl heart organize it make up. In each ovule, generally have master cells of a big spore, after meiosis, forming the big spores of 4 monoploids, 3 among them degradate quickly, only a big spore is has silks that are split for several times, produce the embryo bag of many cells (namely female gametophyte).
In addition, the base department of every part of the flower often has nectaries, is called the nectary in the flower.
A flower, if have such 4 parts as sepal , petal , stamen and pistil ,etc., called the complete flower; If the person who lacks a part among them , is called the imperfect flower. There were the stamens and pistils in a flower, called the hermaphrodite flower; There are only stamens or pistils of some flowers of plant, this kind of flower is called the unisexual flower. Stamen male flower only, pistil female flower only, such as oak tree and flower of the willow. If female flower and male flower with on one, this kind of plant is called the monoecism, such as the oak tree; If female flower and male flower are grown in different plants each, is called the dioecism, such as the willow. Some plants, there can be hermaphrodite flower , male flower and female flower in the same one, and kind that have, plant that has the hermaphrodite flower is female flower plants and male flower plants, such as the kiwi fruit.
Colored mode spend form shape and structure characteristic that plant spend all kinds of , can is it express every permutation form of part of it to come with cross section diagram of flower, called the colored mode. Such as the colored mode picture of the cotton (Fig. 7). Can show with the formula that some symbols and figures arrange , are called the colored form . For example the colored form of the cotton is: K (5+3 ), C5, G (3-5:3- ) of A (¡Þ ), among them K represents calyxes, C represents the petal, A represents stamens, G represents pistils. P representatives spent the quilt. The figure is written in the lower right corner of representative's letter , express with " ¡Þ " such as a lot of of figure, it arrange it spend rounds of more than " + " show, " () "show by joint meaning, whose name is on " G " word or below or adding by one rulering under going to, can part seat room under the representative , go to seat room and half seat room. " G " among there is the digital lower right corner, colon with word ": " Ago it is for carpel number,back for room figure. " * " symbol on it is in front of form not colored , it represents that radiation is symmetrical to spend," "epresenting the bilateral symmetry flower, " ¡â " represents the female flower, " ¡á " represents the male flower , " " expression hermaphrodite flower " ".
Become the colored course plant and grow to reproduction stage, the stem is done to divide and catch organizing to stop the nutrition leaf to take place on upper part or all tops, having turned from growing limitlessly into growing limitedly, the flower can be in the top of the main stem or serving happenning in side shoot , or happen in two places . Cheng Hua of a lot of plants, includes the forming of inflorescence.
When reproduction begins at stage, it is aptest to see the phenomenon is the fast growth of the body axle . Very obvious when and have plants of bulb in the grass family plant. Produce the flower or a inflorescence individually on the axle extended. If the flower was grown on the inflorescence of the branch, when producing the axillary bud with higher speed, close to into a flower too.
It is that the inherent hereditary gene determine by the plant to become flowers and lead the period (or the period of division called bud ) and way that the flower forms. The plant only finishes nutrition and grows, and under a certain external environment, reach certain reproduction at the time of stage, could become flowers . The plant grows after certain stage to could become flowers , in case of great majority, determine by illumination and temperature environmental factor a lot of plant and temperature have sure need ranges to day and night relative change (photoperiod ) of length, under the influence of synthesis of these two kinds of factors, enter reproduction period.
When bring out taking on the top, in fact fen grow and organize cells to change very greatly on the stem end of nutrition. The cytoplasm becomes strong obviously at this moment, the big vacuole that had originally, disperse and become a lot of small vacuoles. Other cell devices , especially the figure of mitochondria greatly increases, the breathing of the cell is strengthened. Later, the small vacuole obviously increases and changes big, and the increase with the cell nucleus, the volume of the kernel increases notably too. In the cell nucleus of this kind of increase, the rates of scattered chromosome and chromatin concentrated , that is bringing out is born and organized higher than what the nutrition stem is served. Top at this moment divide cell organized to give birth to, RNA is it accelerate to formate, with new ribose forming of body, the quantity of total protein increases too. In addition, it is early with becoming the stimulus of the colored factor, it is very vigorous to divide and grow the cell division organized on the top, there is the silk that splits the index and rises suddenly.
After bringing out one, the ones that have evoked DNA are synthetic too with silk separatist activities furtherly. In this way, the quantity of the cell greatly increases, thus the original base of the flower appears. Take place course , that is colored shape period of taking place that point usually while being the above-mentioned. Cheng Hua, fen grow the emergence top organized and divide growing to organize after entering into reproduction period, there is quite obvious shape that changes. Between change and nutrition these that stage grow limitlessly to stop and various kinds of way produce side catch attaching to device have close relations. In the period of growing of nutrition, divide and grow to organize before new leaf interval begin on the top, grow and increase widely upwards. On the contrary, in the colored development, the ones that divided and grew to organize with colored organ on the top recured, the area reduces gradually. Some flower until carpel take place , retain some top of quantity divide and catch the organization, but stop activity, and plant that have, divide by top top part organized to catch produce the carpel. Being different kinds of, one that is according to flower spend organ can become spiral order take place to the top; Or a certain organ (such as the petal), transform into the same level one or two, then another organ is like the stamen group, and then happen.