mani24 29,665 اشتراک گذاری ارسال شده در 8 دی، ۱۳۹۱ [h=2]انواع گل اذین ها[/h] Inflorescences: How flowers are arrenged on the stem [TABLE=class: cms_table, align: center] [TR] [TH=align: center] Shape [/TH] [TH=align: center] Name and Description [/TH] [TH=align: center] Example [/TH] [/TR] [TR] [TD][/TD] [TD]SingleSometimes, there is only one flower on each stem, or the flowers are borne so far apart that they cannot be described as being part of the same flowering cluster. They are often large flowers, so do not need the support of other flowers to attract pollinators. The example is Papaver orientale. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]SpikeA Spike is a group of flowers arising from the main stem, without individual flower stalks (sessile). The example is Agastache foeniculum. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]RacemeA Raceme is a flower spike where the flowers have stalks of equal length, and the tip of the stem continues to grow and produce more flowers. Flowers open from the bottom up. The example is Linaria vulgaris. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]PanicleA Panicle is a branched raceme, each branch having a smaller raceme of flowers. The terminal bud of each branch continues to grow, producing more side shoots and more flowers. The example is Lagerstroemia indica. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]CymeA Cyme is a group of flowers in which the end of each growing point produces a flower, so new growth comes from side shoots and the oldest flowers are at the top. The example is Geranium pratense. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]VerticillasterA Verticillaster is a whorled inflorescence, where the flowers are borne in rings at intervals up the stem. The tip continues to grow, producing more whorls. This type of inflorescence is common in members of the Deadnettle/Mint Family (Lamiaceae). The example is Phlomis russelliana. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]CorymbA Corymb is a flower cluster where all the flowers are at the same level, with flower stalks of different lengths, forming a flat-topped flower cluster. The example is Achillea millefolium. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]UmbelAn Umbel is a flower head in which all the flower stalks are of the same length, so that the flower head is rounded like an umbrella. Many bulbs have this type of flower head. The example is Nerine bowdenii. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]Compound UmbelA Compound Umbel is an umbel where each stalk of the umbel produces a smaller umbel of flowers. This type of inflorescence is typical of members of the Celery Family (Apiaceae). The example is Crithmum maritimum. [/TD] [TD][/TD] [/TR] [TR] [TD][/TD] [TD]CapitulumA Capitulum is a flower head composed of many separate unstalked flowers close together. This type of inflorescence is typical of the Daisy Family (Asteraceae), where the outer flowers have one conspicuous large petal and the central disk is formed of flowers with smaller petals. The example is a Senecio species. [/TD] [TD][/TD] [/TR] [/TABLE] Like everything else in nature, these descriptions can only be a general guide to how your flowers might look. There are many variables, even on one plant, and flower clusters are often described as raceme-like cymes, or cymose panicles, or other words that indicate that the flowers do not conform exactly to any one type of inflorescence. The habit of growth may also be affected by growing conditions, so something that produces clear whorls in moist conditions might produce flowers closer together to form a denser spike in drier conditions. I generally refer to anything in long, thin inflorescences as a spike, and anything more rounded as a cluster. Knowing how a flower head is composed can give you an idea of how many seeds it might produce. Every flower can produce its own seed, so a multiple flower head can theoretically produce many seeds. In practice, particularly in the case of members of the Daisy Family (Asteraceae), not all the seeds develop, which might indicate that pollinators miss some flowers when they are packed closely 2 نقل قول لینک به دیدگاه
mani24 29,665 مالک اشتراک گذاری ارسال شده در 8 دی، ۱۳۹۱ [h=2]Flower Structure and Function[/h] Flowering plants are the dominant type of plants on the earth today (there are about 250000 species). Flowers are therefore the most common plant organs for ***ual reproduction. Flowers produce gametes (*** cells). Flowers play a key role in pollination. Pollination is the transfer of pollen (containing the male gametes), from the anther of a flower, to the stigma (receptive surface of the female part of the flower) of the same or a different flower. Parts of the Flower: [TABLE=class: cms_table, width: 0] [TR] [TD=width: 25%, align: center] Flower Part [/TD] [TD=width: 75%, align: center] Form and Function [/TD] [/TR] [TR] [TD=width: 25%] Peduncle [/TD] [TD=width: 75%] Flower stalk. [/TD] [/TR] [TR] [TD=width: 25%] Receptacle [/TD] [TD=width: 75%] Part of flower stalk bearing the floral organs, at base of flower. [/TD] [/TR] [TR] [TD=width: 25%] Sepal [/TD] [TD=width: 75%] Leaf-like structures at flower base, protects young flower bud. [/TD] [/TR] [TR] [TD=width: 25%] Calyx [/TD] [TD=width: 75%] All the sepals together form the calyx. [/TD] [/TR] [TR] [TD=width: 25%] Petal [/TD] [TD=width: 75%] Located in and above the sepals, often large and colourful, sometimes scented, sometimes producing nectar. Often serve to attract pollinators to the plant. [/TD] [/TR] [TR] [TD=width: 25%] Corolla [/TD] [TD=width: 75%] All the petals together form the corolla. [/TD] [/TR] [TR] [TD=width: 25%] Stamen [/TD] [TD=width: 75%] Male part of the flower, consisting of the anther and filament, makes pollen grains. [/TD] [/TR] [TR] [TD=width: 25%] Filament [/TD] [TD=width: 75%] The stalk of the stamen which bears the anther. [/TD] [/TR] [TR] [TD=width: 25%] Anther [/TD] [TD=width: 75%] The pollen bearing portion of a stamen. [/TD] [/TR] [TR] [TD=width: 25%] Pollen [/TD] [TD=width: 75%] Grains containing the male gametes. Immature male gametophyte with a protective outer covering. [/TD] [/TR] [TR] [TD=width: 25%] Carpel\Pistil [/TD] [TD=width: 75%] Female part of the flower. Consisting of the stigma, style and ovary. [/TD] [/TR] [TR] [TD=width: 25%] Stigma [/TD] [TD=width: 75%] Often sticky top of carpel, serves as a receptive surface for pollen grains. [/TD] [/TR] [TR] [TD=width: 25%] Style [/TD] [TD=width: 75%] The stalk of a carpel, between the stigma and the ovary, through which the pollen tube grows. [/TD] [/TR] [TR] [TD=width: 25%] Ovary [/TD] [TD=width: 75%] Enlarged base of the carpel containing the ovule or ovules. The ovary matures to become a fruit. [/TD] [/TR] [TR] [TD=width: 25%] Ovule [/TD] [TD=width: 75%] Located in the ovaries. Carries female gametes. Ovules become seeds on fertilization. [/TD] [/TR] [/TABLE] The *** of a flower can be described in three ways: Staminate flowers: Flowers bearing only male *** parts. These are sometime referred to as "male flowers". Carpellate\Pistillate Flowers: Flowers bearing only female *** parts. These are sometimes referred to as "female flowers". Hermaphhrodite\Complete flowers: Flowers bearing both male and female *** parts. In many cases flowers are borne as a group on a common stalk, called an inflorescence. They are many different types of floral inflorescences. The type of inflorescence present is sometimes used to aid in classifying flowering plants. Below are a number of common floral inflorescences. Flowers are sometimes associated with prominent, often brightly coloured leaves called bracts. In some instances (like in bougainvilleas, heliconias and ginger lillies), the bracts are even more colourful and outstanding than the flowers they surround. [TABLE=class: cms_table] [TR] [TD] [/TD] [TD] In the heliconia cultivar on the left, the large yellow and red structures are bracts, while the small yellow structures within them are the actual flowers. [/TD] [/TR] [TR] [TD=width: 50%] The yellow shrimp plant, has large, showy yellow bracts, and smaller white flowers. [/TD] [TD=width: 50%] [/TD] [/TR] [/TABLE] 2 نقل قول لینک به دیدگاه
mani24 29,665 مالک اشتراک گذاری ارسال شده در 8 دی، ۱۳۹۱ The sum of all flowers of a plant is called inflorescence. Inflorescences exist in many different forms and shapes, so in this week's “Article of the Weel” I want to show the basic and common variants of inflorescences. I'll not show all of them, but only the main types. So first, let us check out some basic terms. When you look at an inflorescence, you have maybe noticed, that some of them are ending into a terminal flower and others not. In Botany we speak of amonotelic(closed) inflorescence in first case and of a polytelic (opened) inflorescence in the second It's also makes a different, if an inflorescence only consists of single flowers or in turn are compounded of small inflorescences by itself. First we look at inflorescences, which consist only of single flowers. I. simple Inflorescences برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام a)ear: the ear is possible the most simple type of an inflorescence. Here, the flowers are sitting directly into the axil of their bracts. Ears can be found at some species of the Poaceae (e. g. the Genus ofHordeum), but also at the Genus Plantago. A cone is also a variant of an ear. b) raceme: the raceme is not very different from the ear. The only difference is, that the flowers of a raceme are sitting at the end of a short stalk, growing from the axil of a bract. This type of inflorescence can be found e. g. at the Genus of Viccia. برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام c) umbel: At the umbel, the flowers also are sitting on a stalk. All stalks starts at the same point of the shoot axis. The bracts of the flowers often forms a such called involucrum. So the whole inflorescence looks like a umbrella.Umbels are the typical character for the Apiaceae family, which is also calledUmbeliferaceae. Be careful, because sometimes, a raceme is formed like an umbrella (e. g. at Capsella bursa-pastoris L.), but this are no real umbels, because here the stalks are not starting at the same point. Sometimes, an umbel consists of smaller umbels. This is a double-umbel (d) برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام e) & f): catkin: a catkin in basically no more than an inverted and hanging ear or raceme. This type of inflorescence is typical for many genera of our native trees like Alnus, Populus or Salix. برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام note: in this picture the small bracts of the spadix and the head 1 has not be draw g) spadix: A spadix is a special type of an ear, but here, the floral axis is thickened and cylindrical. Spadices can be found e.g. at Zea mays L. (corn) and the most species from the Araceae. They are also typical for the Genus Typha (bullrush or corndog grass)of the Typhaceae. e) head 1:The first type of the head-formed inflorescence is similar to the spadix. The transition is fluently indeed. The flora axis is also thickened but more jolted. This inflorescence is typical for theTrifoliumGenus (e. g. Trifolium medium ssp. medium L. in this Blog) f) head 2: The second head inflorescence is the characteristic inflorescence of the Asteraceae family (with species like common daisy, common dandelion or the sun flower). Here the floral axis is compressed even more than the first head type. The flowers are sitting directly at this floral axis and their bracts are forming a involucrum. II. compounded inflorescences O.k. Folks, now it becomes complicated. In the previous inflorescences we always have a single flower per bract. But sometimes, a inflorescence is multi-branched, that means instead of a flower it has smaller floral axis, growing out from the axial of the bracts. In this case it depends on how the inflorescence is branched. First, we have two basic types again: the panicle and the cyme. برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام a) panicle: At a panicle, a new floral axis grows from a single bract. This axis can be branched by itself. The branching doesn't follow a strict scheme and flowers can grow everywhere. A panicle is always monotelic. b) cyme: If the successive branches follows a scheme, we speak of a cyme. If there is only one new axis per branching, we call it a monochasium. With two new axis per branching, we called dichasium. Now we subdivide the monochasial and dichasial cymes into three types again. برای مشاهده این محتوا لطفاً ثبت نام کنید یا وارد شوید. ورود یا ثبت نام c) thyrse: A thyrse is simply a inflorescence with dichasial cymes as branches. The inflorescence of Aesculus hippocastanum L. (conker tree) is a good example for a thyrse d) depranium: A depranium is a monochasial cyme. Here, the floral axis are helical applied towards the main axis. e) rhipidium: The rhipidium is basically the opposite of the depranium. The successive floral axis grow in a zigzag pattern. The inflorescence of the tomato is e. g. a rhipidium 2 نقل قول لینک به دیدگاه
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