The individual flower organs are arranged in the angiosperms within the flower in a specific order from bottom to top, respectively, as the flower axis is so compressed, from outside to inside. In that order, they are also ontogenetically (created during the flowering).
The flowers envelope (perianth) are sterile leaves, however, definitely belong to the flower. A perianth is formed only by Gnetopsida and Angiosperms. Are all the bracts in a uniform format, which is called the perianth perianth, the leaves as tepals (such as the tulip). Here, the perianth of a circle (monochlamydeisch), there are two or more circles or more Schraubenumläufen (homoiochlamydeisch). A double perianth (flower heterochlamydeische) consists of dissimilar petals. Which are external, mostly green, the sepals (sepals) and form the cup (Calyx), the internal, often strikingly colored leaves, the petals (petals) and form the crown (Corolla). The evolutionary origin of the perianth is interpreted according to the lineage from bracts or from stamens.
Mikrosporophylle with many sporangia in cycads Ceratozamia
Many monocots have six stamens (here Hemerocallis)
Mikrosporophylle are sporangientragende leaves. In the sporangia (pollen sacs), male microspores are formed. The Mikrosporophylle, depending on the seed plants group trained very differently, and a homology to the leaves (φύλλον phyllon, - "Leaf") is not fully understood. Neutral Mikrosporangienträger they could therefore be named. When the Ginkgo Mikrosporophyll a stick, hung at the head of two pollen sacs, the Mikrosporophylle is available to many spirally on the flower axis. For conifers, the male flower peg and usually consists of many spirally arranged Mikrosporophyllen; every Mikrosporophyll Two to 20 pollen sacs. In the cycads (cycads) are the scale-Mikrosporophylle and take five to 1,000 pollen sacs, which are spirally Mikrosporophylle in the male flower. In the six Welwitschie fused Mikrosporophylle take three pollen sacs. In Gnetum Mikrosporophyll sustains the only one or two terminal pollen sacs. With Ephedra is the Mikrosporophyll often forked and bears two to eight groups of usually two fused pollen sacs.
The stamens are Mikrosporophylle of angiosperms (called Stamina). A stamen is usually in the stamen (filament) and anthers (anther) divided. The latter consists of two connected by the connective counters to two pollen sacs. The totality of the stamens is called androecium. The number of stamens per flowers varies between one and about 2000 pieces.
Megasporophyll with ripe seeds of cycads, Dioon edule
The Megasporophylle bear the characteristic of the seed plant ovules, the structures in which the female reproductive organs are formed. They could also be described as neutral Megasporangienträger. Only the Megasporophylle the angiosperms are known as carpel.
In the cycads, the ovules are clearly on leaves, they are phyllospor. The scale or peltate Megasporophyll is stalked and contributes significantly to the lower edge of the blade has two ovules in Cycas are up to eight ovules along the rachis. The conifers are a 20 seed to plant on the surface is extensive seed scale. The seed scale is a modified short shoots. Rare plants are the seeds of conifers terminal to short branches, as in the yew (Taxus). Ginkgo is formed at the tip of a bifurcated stem two ovules. The Gnetopsida form per flower only one terminal ovule.
In the angiosperms the ovules in the carpel (carpel are included), hence the name "angiosperms". The totality of the carpel forms the gynoecium. The number of carpels per flower is between one and around 2000. Mostly, a fruit leaf stalk is divided into a zone and a tubing area, the hollow area where are the seeds of plants (also called the ovary). The ovules are based upon placentas. It often includes a pen, where is the scar, the Conception area for the pollen. The scar is connected by a transmission channel or tissues to the ovules. The fruit leaves can be freely (or apokarpes chorikarpes gynoecium) or be fused together (coenokarp). With a fused gynoecium is called a punch (pestle). Sterile flowers have a maximum reduction of dust and leaves and fruit often have the function of a display apparatus.
Androgynophor the passion flower. The top three long red Griffeläste, including five stamens
At the floral axis (receptacle or receptacle) to put the petals. It can be compressed stretched and shaped differently. There may be one or more whorl uplifted by intercalary meristems: gynoecium (Gynophor, for example in the caper), gynoecium and androecium (Androgynophor, such as Passion Flower), or gynoecium, androecium and crown (Anthophor, many carnation family).
It can also be raised circular areas around the center. One example is a Stamen-Corollentubus, as is typical in many composites, or the cup-Kronbecher many cucurbits. A wider flower axis means flower cup (hypanthium). All parts are lifted except the ovary, to go to floral tube, which bears the perianth and the stamens. The result is a perigyner flower cup. The ovary is then called the midline. A oberständiger ovary is free on the flower axis. If involved in a floral cup, the outer leaves of the fruit, there arises an inferior ovary, which means he is below the perianth.
Nectaries are glands that make nectar for pollinators as a bait. It usually consists of a sugar solution which may contain proteins, amino acids and vitamins. Rare oils are formed (for example in Lysimachia, Lysimachia). Nectaries can from the perianth, the stamens, the ovary, the flower axis, but also be formed outside of the actual flower (extrafloral).
Position and arrangement
The petals may vary after spirally leaf position (phyllotaxis) to the flower axis (acyclic) or whorls (cycles can be arranged). A screw-like arrangement is widely regarded as a primitive feature and is often associated with a higher number of petals joined. The angle between two successive leaves is usually near the golden section angle of about 137.5 °.
Frequently, only a part of the petals is spirally, while the inner petals are arranged in whorls. These flowers are known as spirocyclic or hemicycles. A transition from spirally formed whorls to the fact that as in the Yulan magnolia (Magnolia denudata) for each of three leaves a break in the sheet formation occurs, so that there are three-fold approach in whorls. Even with many farmers celled flowers in the development of a spirally order of leaf formation can be seen, the leaves of circles but are so close together that creates a whorl.
When farmers celled position in each whorl or circle are only one type of flower petals. With the intelligent position of farmers is also accompanied by a reduction in the number of petals (oligomeric circles). Most farmers have four-celled hermaphrodite flowers (tetracyclic flower) or five (pentacyclic) whorls: sepal-one, one petal, one or two stamen and a carpel-whorl. In most angiosperms, the number of leaves per whorl is fixed, then accordingly we speak of two-, three-, four-or fivefold flowers. Do all groups the same number of members, is the flower isomer (such as the tulip), this is not the case, the flower is heteromeric.
The leaves are usually in whorls of each other standing gap (Alternanzprinzip), which means the members of the next inner whorl stand in the gap between two members of the previous whorl. In pentacyclic flowers often occurs on the case that the inner stamen circle is pushed through the ovary to the outside and so apparently is the outer. This phenomenon is called Obdiplostemonie. All the petals can be with their own kind or with other more or less deformed.
Can be laid by a bloom more than three planes of symmetry, it is somewhat further (as the tulip). When two planes of symmetry is disymmetrisch such Dicentra. A plane of symmetry have zygomorph (dorsiventral) flowers. Usually this symmetry plane in the median plane of the flower runs (that is, by and shoot axis of the bract bract), as in the Lamiaceae, rarely perpendicular to the median level, such as in Corydalis. Asymmetric flowers have no symmetry plane. Strictly spirally flowers are also taken on this, but are usually regarded as somewhat further. The ratios of the flower parts may be presented in graphical charts, flowers or flower formulas.
Often, several or many individual flowers are united into flowers.
The original form of the angiosperms are hermaphroditic flowers. There are unisexual flowers (unisexual), the organs of the opposite sex are usually available as well as rudiments: There are staminate (male) and pistillate ("female") flowers. Taxa with unisexual flowers and plants can be monoecious (monoecious, male and female flowers on a plant) or dioecious (dioecious, male and female flowers on different plants) be. Polygamous plants have both hermaphroditic as unisexual flowers.
Source : http://de.wikipedia.org/wiki/Bl%C3%BCte