In botany, stipule is a term coined by Linnaeus which refers to outgrowths borne on either side of the base of a leafstalk. A pair of stipules is considered part of the anatomy of the leaf of a typical flowering plant, although in many species the stipules are inconspicuous or absent. In some older botanical writing, the term "stipule" was used more to refer to any small leaves or leaf-parts, notably prophylls; the position of stipules on a plant varies from species to species, though they are located near the base of a leaf. Stipules are most common on dicotyledons; some monocotyledon plants only display one per leaf. A relationship exists between the anatomy of the stem node and the presence or absence of stipules: most plants with trilacunar nodes have stipules. Stipules are morphologically variable and might appear as glands, hairs, spines, or laminar structures. If a single stipule goes all the way around the stem, it is known as an ochrea; the three types of stipules according to duration are caducous and persistent.
Caducous stipules fall off before the leaf unfolds, while deciduous stipules fall off after the leaf unfolds. Persistent stipules remain attached to the plant. Stipules can be considered free lateral, interpetiolar, ochreate, bud scales, tendrillar or spiny. A stipule can be fused to the other stipule from the same node. A stipule is "adnate" if it's fused together on part of the petiole length, but the anterior is still free. A stipule is "interpetiolar" if it is located in between the petioles, as opposed to being attached to the petioles, one stipule from each leaf is fused together, so it appears that there's just one stipule between each leaf. A stipule is "intrapetiolar" if it is located in the angle that's between a petiole. In this case, the two stipules form together and appear to be one stipule. A stipule is "ochreate" if a single stipule appears to be a solid tube that goes all the way around the stem. A stipule is "foliaceous"; these are used to photosynthesize. A stipule protects leaf buds as they form.
These fall off as soon as the leaf unfolds. A stipule is considered "tendrillar" if they are long thin tendrils, are used by climbing plants. A stipule is considered "spiny" if they are pointy; these are used to deter animals. A stipule is considered to be "abaxial", "counter" or "leaf opposed" if it's located on the opposite side to where the leaf meets the stem. Stipules have various functions; some stipules may be vestigial. It is known. Sometimes stipules protect the next leaf or bud as it grows in falls off after the leaf unfolds, as with Tulip Poplars. Stipules can be used as climbing tendrils by climbing plants. Spiny stipules can be used to help protect the plant from animals. Esau, K. 1953. Plant Anatomy. Second Edition. John Wiley & Sons, Inc. New York, Sidney. 767 pp. Stipules and stipels
Fossilworks is a portal which provides query and analysis tools to facilitate access to the Paleobiology Database, a large relational database assembled by hundreds of paleontologists from around the world. Fossilworks is housed at Macquarie University, it includes many analysis and data visualization tools included in the Paleobiology Database. "Fossilworks". Retrieved 2010-04-08
A sepal is a part of the flower of angiosperms. Green, sepals function as protection for the flower in bud, as support for the petals when in bloom; the term sepalum was coined by Noël Martin Joseph de Necker in 1790, derived from the Greek σκεπη, a covering. Collectively the sepals are called the outermost whorl of parts that form a flower; the word calyx was adopted from the Latin calyx, not to be confused with a cup or goblet. Calyx derived from the Greek κάλυξ, a bud, a calyx, a husk or wrapping, while calix derived from the Greek κυλιξ, a cup or goblet, the words have been used interchangeably in botanical Latin. After flowering, most plants have no more use for the calyx which becomes vestigial; some plants retain a thorny calyx, either dried or live, as protection for seeds. Examples include species of Acaena, some of the Solanaceae, the water caltrop, Trapa natans. In some species the calyx not only persists after flowering, but instead of withering, begins to grow until it forms a bladder-like enclosure around the fruit.
This is an effective protection against some kinds of birds and insects, for example in Hibiscus trionum and the Cape gooseberry. Morphologically, both sepals and petals are modified leaves; the calyx and the corolla are the outer sterile whorls of the flower, which together form what is known as the perianth. The term tepal is applied when the parts of the perianth are difficult to distinguish, e.g. the petals and sepals share the same color, or the petals are absent and the sepals are colorful. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, an alternative name is lilioid monocots. Examples of plants in which the term tepal is appropriate include genera such as Tulipa. In contrast, genera such as Rosa and Phaseolus have well-distinguished petals; the number of sepals in a flower is its merosity. Flower merosity is indicative of a plant's classification.
The merosity of a eudicot flower is four or five. The merosity of a monocot or palaeodicot flower is a multiple of three; the development and form of the sepals vary among flowering plants. They may be fused together; the sepals are much reduced, appearing somewhat awn-like, or as scales, teeth, or ridges. Most such structures protrude until the fruit is mature and falls off. Examples of flowers with much reduced perianths are found among the grasses. In some flowers, the sepals are fused towards the base. In other flowers a hypanthium includes the bases of sepals and the attachment points of the stamens. Plant morphology
Endemism is the ecological state of a species being unique to a defined geographic location, such as an island, country or other defined zone, or habitat type. The extreme opposite of endemism is cosmopolitan distribution. An alternative term for a species, endemic is precinctive, which applies to species that are restricted to a defined geographical area; the word endemic is from New Latin endēmicus, from Greek ενδήμος, endēmos, "native". Endēmos is formed of en meaning "in", dēmos meaning "the people"; the term "precinctive" has been suggested by some scientists, was first used in botany by MacCaughey in 1917. It is the equivalent of "endemism". Precinction was first used by Frank and McCoy. Precinctive seems to have been coined by David Sharp when describing the Hawaiian fauna in 1900: "I use the word precinctive in the sense of'confined to the area under discussion'...'precinctive forms' means those forms that are confined to the area specified." That definition excludes artificial confinement of examples by humans in far-off botanical gardens or zoological parks.
Physical and biological factors can contribute to endemism. The orange-breasted sunbird is found in the fynbos vegetation zone of southwestern South Africa; the glacier bear is found only in limited places in Southeast Alaska. Political factors can play a part if a species is protected, or hunted, in one jurisdiction but not another. There are two subcategories of endemism: neoendemism. Paleoendemism refers to species that were widespread but are now restricted to a smaller area. Neoendemism refers to species that have arisen, such as through divergence and reproductive isolation or through hybridization and polyploidy in plants. Endemic types or species are likely to develop on geographically and biologically isolated areas such as islands and remote island groups, such as Hawaii, the Galápagos Islands, Socotra. Hydrangea hirta is an example of an endemic species found in Japan. Endemics can become endangered or extinct if their restricted habitat changes, particularly—but not only—due to human actions, including the introduction of new organisms.
There were millions of both Bermuda petrels and "Bermuda cedars" in Bermuda when it was settled at the start of the seventeenth century. By the end of the century, the petrels were thought extinct. Cedars ravaged by centuries of shipbuilding, were driven nearly to extinction in the twentieth century by the introduction of a parasite. Bermuda petrels and cedars are now rare. Principal causes of habitat degradation and loss in endemistic ecosystems include agriculture, urban growth, surface mining, mineral extraction, logging operations and slash-and-burn agriculture
Petals are modified leaves that surround the reproductive parts of flowers. They are brightly colored or unusually shaped to attract pollinators. Together, all of the petals of a flower are called a corolla. Petals are accompanied by another set of special leaves called sepals, that collectively form the calyx and lie just beneath the corolla; the calyx and the corolla together make up the perianth. When the petals and sepals of a flower are difficult to distinguish, they are collectively called tepals. Examples of plants in which the term tepal is appropriate include genera such as Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished petals; when the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, an alternative name is lilioid monocots. Although petals are the most conspicuous parts of animal-pollinated flowers, wind-pollinated species, such as the grasses, either have small petals or lack them entirely.
The role of the corolla in plant evolution has been studied extensively since Charles Darwin postulated a theory of the origin of elongated corollae and corolla tubes. A corolla of separate tepals is apopetalous. If the petals are free from one another in the corolla, the plant is choripetalous. In the case of fused tepals, the term is syntepalous; the corolla in some plants forms a tube. Petals can differ in different species; the number of petals in a flower may hold clues to a plant's classification. For example, flowers on eudicots most have four or five petals while flowers on monocots have three or six petals, although there are many exceptions to this rule; the petal whorl or corolla may be bilaterally symmetrical. If all of the petals are identical in size and shape, the flower is said to be regular or actinomorphic. Many flowers are termed irregular or zygomorphic. In irregular flowers, other floral parts may be modified from the regular form, but the petals show the greatest deviation from radial symmetry.
Examples of zygomorphic flowers may be seen in members of the pea family. In many plants of the aster family such as the sunflower, Helianthus annuus, the circumference of the flower head is composed of ray florets; each ray floret is anatomically an individual flower with a single large petal. Florets in the centre of the disc have no or reduced petals. In some plants such as Narcissus the lower part of the petals or tepals are fused to form a floral cup above the ovary, from which the petals proper extend. Petal consists of two parts: the upper, broad part, similar to leaf blade called the blade and the lower part, similar to leaf petiole, called the claw, separated from each other at the limb. Claws are developed in petals of some flowers such as Erysimum cheiri; the inception and further development of petals shows a great variety of patterns. Petals of different species of plants vary in colour or colour pattern, both in visible light and in ultraviolet; such patterns function as guides to pollinators, are variously known as nectar guides, pollen guides, floral guides.
The genetics behind the formation of petals, in accordance with the ABC model of flower development, are that sepals, petals and carpels are modified versions of each other. It appears that the mechanisms to form petals evolved few times, rather than evolving from stamens. Pollination is an important step in the sexual reproduction of higher plants. Pollen is produced by the male organs of hermaphroditic flowers. Pollen does not move on its own and thus requires wind or animal pollinators to disperse the pollen to the stigma of the same or nearby flowers. However, pollinators are rather selective in determining the flowers; this develops competition between flowers and as a result flowers must provide incentives to appeal to pollinators. Petals play a major role in competing to attract pollinators. Henceforth pollination dispersal could occur and the survival of many species of flowers could prolong. Petals have various purposes depending on the type of plant. In general, petals operate to protect some parts of the flower and attract/repel specific pollinators.
This is where the positioning of the flower petals are located on the flower is the corolla e.g. the buttercup having shiny yellow flower petals which contain guidelines amongst the petals in aiding the pollinator towards the nectar. Pollinators have the ability to determine specific flowers. Using incentives flowers draw pollinators and set up a mutual relation between each other in which case the pollinators will remember to always guard and pollinate these flowers; the petals could produce different scents to allure desirable pollinators or repel undesirable pollinators. Some flowers will mimic the scents produced by materials such as decaying meat, to attract pollinators to them. Various colour traits are used by different petals that could attract pollinators that have poor smelling abilities, or that only come out at certain parts of the day; some flowers are able to change the colour
In the flowering plants, an ovary is a part of the female reproductive organ of the flower or gynoecium. It is the part of the pistil which holds the ovule and is located above or below or at the point of connection with the base of the petals and sepals; the pistil may be made up of one carpel or of several fused carpels, therefore the ovary can contain part of one carpel or parts of several fused carpels. Above the ovary is the style and the stigma, where the pollen lands and germinates to grow down through the style to the ovary, for each individual pollen grain, to fertilize one individual ovule; some wind pollinated flowers have much modified ovaries. A fruit is ovaries -- together with seeds -- from one or more flowers; the fruits of a plant are responsible for dispersing the seeds that contain the embryo and protecting the seeds as well. In many species, the fruit incorporates some surrounding tissues, or is dispersed with some non-fruit tissues. Locules are chambers within the ovary of fruits.
The locules contain the ovules, may or may not be filled with fruit flesh. Depending on the number of locules in the ovary, fruits can be classified as uni-locular, bi-locular, tri-locular or multi-locular; some plants have septa between the carpels. The ovules are attached to parts of the interior ovary walls called the placentae. Placental areas occur in various positions, corresponding to various parts of the carpels that make up the ovary. See Ovule#Location within the plant. An obturator is present in the ovary of some plants, near the micropyle of each ovule, it is an outgrowth of the placenta, important in nourishing and guiding pollen tubes to the micropyle. The ovary of some types of fruit is dehiscent. There is the position of the septa; the terminology of the positions of ovaries is determined by the insertion point, where the other floral parts come together and attach to the surface of the ovary. If the ovary is situated above the insertion point, it is superior. A superior ovary is an ovary attached to the receptacle above the attachment of other floral parts.
A superior ovary is found in types of fleshy fruits such as true berries, etc. A flower with this arrangement is described as hypogynous. Examples of this ovary type include the legumes. A half-inferior ovary is surrounded by the receptacle; this occurs in flowers of the Lythraceae family. Such flowers are termed half-epigynous. In some classifications, half-inferior ovaries are not recognized and are instead grouped with either the superior or inferior ovaries. More a half-inferior ovary has nearly equal portions of ovary above and below the insertion point. Other varying degrees of inferiority can be described by other fractions. For instance, a "one-fifth inferior ovary" has one fifth of its length under the insertion point. Only one quarter portion of a "three-quarters inferior ovary" is above the insertion. An inferior ovary lies below the attachment of other floral parts. A pome is a type of fleshy fruit, cited as an example, but close inspection of some pomes will show that it is a half-inferior ovary.
Flowers with inferior ovaries are termed epigynous. Some examples of flowers with an inferior ovary are orchids, banana and the pepo of the squash and gourd family. Fruit anatomy
In botany, the receptacle refers to vegetative tissues near the end of reproductive stems that are situated below or encase the reproductive organs. In angiosperms, the receptacle or torus is the thickened part of a stem from which the flower organs grow. In some accessory fruits, for example the pome and strawberry, the receptacle gives rise to the edible part of the fruit; the fruit of Rubus species is a cluster of drupelets on top of a conical receptacle. When a raspberry is picked, the receptacle separates from the fruit, but in blackberries, it remains attached to the fruit. In the Daisy family, small individual flowers are arranged on a round or dome-like structure, called receptacle. In phycology, receptacles occur at the ends of branches of algae in the brown algae or Heterokontophyta in the Order Fucales, they are specialised structures. Receptacles function as a structure that captures food