Petals are modified leaves that surround the reproductive parts of flowers . They are often brightly coloured or unusually shaped to attract pollinators . All of the petals of a flower are collectively known as the corolla . Petals are usually accompanied by another set of modified leaves called sepals , that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth , the non-reproductive portion of a flower. 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 Aloe and Tulipa . Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and 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.
40-424: Ranunculus / r æ ˈ n ʌ ŋ k j ʊ l ə s / is a large genus of about 1750 species of flowering plants in the family Ranunculaceae . Members of the genus are known as buttercups , spearworts and water crowfoots . The genus is distributed worldwide, primarily in temperate and montane regions. The familiar and widespread buttercup of gardens throughout Northern Europe (and introduced elsewhere)
80-434: A cyme , have usually five (but occasionally as few as three or as many as seven) sepals and usually, five yellow, greenish or white petals that are sometimes flushed with red, purple or pink (but the petals may be absent or have a different, sometimes much higher number). At the base of each petal is usually one nectary gland that is naked or may be covered by a scale. Anthers may be few, but often many are arranged in
120-494: A 2004 analysis by the botanical taxonomist David G. Frodin , a total of 57 genera of flowering plants contain at least 500 species. It is clear that there are other genera with over 500 species, as the work of taxonomists continues. Currently the number of species included in many genera is very different (e.g. see Psychotria ), so their ranking is subject to changes. The actual numbers of species are imprecisely known also because of different approaches of taxonomists, and many of
160-407: A 2010 classification for the tribe Ranunculeae. The split (and often re-recognized) genera include Arcteranthis Greene, Beckwithia Jeps., Callianthemoides Tamura, Coptidium (Prantl) Beurl. ex Rydb., Cyrtorhyncha Nutt. ex Torr. & A.Gray, Ficaria Guett., Krapfia DC., Kumlienia E. Greene and Peltocalathos Tamura. Not all taxonomists and users accept this splitting of
200-455: A distinction can be made between a lower narrowed, stalk-like basal part referred to as the claw, and a wider distal part referred to as the blade (or limb). Often, the claw and blade are at an angle with one another. Wind-pollinated flowers often have small, dull petals and produce little or no scent. Some of these flowers will often have no petals at all. Flowers that depend on wind pollination will produce large amounts of pollen because most of
240-495: A floral cup ( hypanthium ) above the ovary, and from which the petals proper extend. A petal often consists of two parts: the upper broader part, similar to a leaf blade, also called the blade; and the lower narrower part, similar to a leaf petiole , called the claw , separated from each other at the limb . Claws are distinctly developed in petals of some flowers of the family Brassicaceae , such as Erysimum cheiri . The inception and further development of petals show
280-540: A great variety of patterns. Petals of different species of plants vary greatly in colour or colour pattern, both in visible light and in ultraviolet. Such patterns often function as guides to pollinators and are variously known as nectar guides , pollen guides, and floral guides. The genetics behind the formation of petals, in accordance with the ABC model of flower development , are that sepals, petals, stamens , and carpels are modified versions of each other. It appears that
320-435: A plant's classification. For example, flowers on eudicots (the largest group of dicots ) most frequently 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 either radially or bilaterally symmetrical (see Symmetry in biology and Floral symmetry ). If all of the petals are essentially identical in size and shape,
360-404: A rosette at the base of the stem. In many perennial species runners are sent out that will develop new plants with roots and rosettes at the distanced nodes. The leaves lack stipules , have petioles , are palmately veined , entire, more or less deeply incised, or compound, and leaflets or leaf segments may be very fine and linear in aquatic species. The hermaphrodite flowers are single or in
400-507: A spiral, are yellow or sometimes white, and with yellow pollen . The sometimes few but mostly many green or yellow carpels are not fused and are also arranged in a spiral, mostly on a globe or dome-shaped receptacle . The petals of buttercups are often highly lustrous , especially in yellow species, owing to a special coloration mechanism: the petal's upper surface is very smooth causing a mirror-like reflection. The flash aids in attracting pollinating insects and temperature regulation of
440-563: A third, intermediate leaf type occurs. Ranunculus species are used as food by the larvae of some Lepidoptera species including the Hebrew character and small angle shades . Some species are popular ornamental flowers in horticulture , with many cultivars selected for large and brightly coloured flowers. Buttercups are found in both hemispheres on all continents aside from Antarctica, and are primarily found in temperate or montane habitats. They likely originated in northern Eurasia during
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#1732800842635480-415: A variety of shapes acting to aid with the landing of the visiting insect and also influence the insect to brush against anthers and stigmas (parts of the flower). One such example of a flower is the pohutukawa ( Metrosideros excelsa ), which acts to regulate colour in a different way. The pohutukawa contains small petals also having bright large red clusters of stamens. Another attractive mechanism for flowers
520-418: Is apopetalous . If the petals are free from one another in the corolla, the plant is polypetalous or choripetalous ; while if the petals are at least partially fused, it is gamopetalous or sympetalous . In the case of fused tepals, the term is syntepalous . The corolla in some plants forms a tube. Petals can differ dramatically in different species. The number of petals in a flower may hold clues to
560-435: Is broken down to form protoanemonin , which is known to cause contact dermatitis in humans and care should therefore be exercised in extensive handling of the plants. The toxins are degraded by drying, so hay containing dried buttercups is safe. List of the largest genera of flowering plants There are over 56 genera of flowering plants estimated to contain at least 500 described species . The largest of these
600-536: Is currently the legume genus Astragalus (milk-vetches), with over 3,000 species. The sizes of plant genera vary widely from those containing a single species to genera containing thousands of species, and this disparity became clear early in the history of plant classification. The largest genus in Carl Linnaeus ' seminal Species Plantarum was Euphorbia , with 56 species; Linnaeus believed that no genus should contain more than 100 species. Part of
640-738: Is poisonous to cows and other livestock). A popular children's game involves holding a buttercup up to the chin; a yellow reflection is supposed to indicate a fondness for butter. In ancient Rome, a species of buttercup was held to the skin by slaves attempting to remove forehead tattoos made by their owners. In the interior of the Pacific Northwest of the United States, the buttercup is called "Coyote's eyes"— ʔiceyéeyenm sílu in Nez Perce and spilyaynmí áčaš in Sahaptin . In
680-412: Is the creeping buttercup Ranunculus repens , which has extremely tough and tenacious roots. Two other species are also widespread, the bulbous buttercup Ranunculus bulbosus and the much taller meadow buttercup Ranunculus acris . In ornamental gardens, all three are often regarded as weeds . Buttercups usually flower in the spring, but flowers may be found throughout the summer, especially where
720-702: Is the use of scents which are highly attractive to humans. One such example is the rose. On the other hand, some flowers produce the smell of rotting meat and are attractive to insects such as flies. Darkness is another factor that flowers have adapted to as nighttime conditions limit vision and colour-perception. Fragrancy can be especially useful for flowers that are pollinated at night by moths and other flying insects. Flowers are also pollinated by birds and must be large and colourful to be visible against natural scenery. In New Zealand, such bird–pollinated native plants include: kowhai ( Sophora species), flax ( Phormium tenax ) and kaka beak ( Clianthus puniceus ). Flowers adapt
760-1064: The Rhön Mountains , central Germany . Achenes labelled Ranunculus cf. tachiroei is known from the Pliocene of the Hengduan Mountains of China. Indeterminate achenes have been found from Neogene strata from the Meyer Desert Formation biota in the Transantarctic Mountains , which appear to have inhabited a periglacial environment. The oldest potential fossil is from the Late Eocene (initially identified as Miocene) Florissant Formation of Colorado , identified by Theodore Dru Alison Cockerell in 1922. Buttercups are mostly perennial , but occasionally annual or biennial , herbaceous , aquatic or terrestrial plants, often with leaves in
800-422: 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 typically have no or very reduced petals. In some plants such as Narcissus , the lower part of the petals or tepals are fused to form
840-650: The tropics were grouped into much larger and more heterogeneous genera. Likewise, plants which shared common medicinal properties, such as the many species of Euphorbia , were united into a single genus, while plants of diverse uses, such as the grasses , were split into many genera. Where there were many classical names for groups of plants, such as in Apiaceae / Umbelliferae or Brassicaceae / Cruciferae , small genera were defined, whereas groups not subdivided by classical authors remained as larger genera, such as Carex . A number of biological factors also influence
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#1732800842635880-499: The blistering of the mouth caused by their poison means they are usually left uneaten. Poisoning in livestock can occur where buttercups are abundant in overgrazed fields where little other edible plant growth is left, and the animals eat them out of desperation. Symptoms of poisoning include bloody diarrhea , excessive salivation , colic , and severe blistering of the mouth, mucous membranes and gastrointestinal tract. When Ranunculus plants are handled, naturally occurring ranunculin
920-464: The disparity in genus sizes is attributable to historical factors. According to a hypothesis published by Max Walters in 1961, the size of plant genera is related to the age, not of the taxon itself, but of the concept of the taxon in the minds of taxonomists . Plants which grew in Europe, where most of the early taxonomy was based, were therefore divided into relatively small genera, while those from
960-458: The flower is said to be regular or actinomorphic (meaning "ray-formed"). Many flowers are symmetrical in only one plane (i.e., symmetry is bilateral) and are termed irregular or zygomorphic (meaning "yoke-" or "pair-formed"). 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 orchids and members of
1000-436: The flower's reproductive organs. The fruits (in this case called achenes ) may be smooth or hairy, winged, nobby or have hooked spines. The genus name Ranunculus is Late Latin for "little frog", the diminutive of rana . This probably refers to many species being found near water, like frogs. The common name buttercup may derive from a false belief that the plants give butter its characteristic yellow hue (in fact it
1040-432: The flower/petals are important in selecting the type of pollinators they need. For example, large petals and flowers will attract pollinators at a large distance or that are large themselves. Collectively, the scent, colour, and shape of petals all play a role in attracting/repelling specific pollinators and providing suitable conditions for pollinating. Some pollinators include insects, birds, bats, and wind. In some petals,
1080-400: The genera have not been the subject of recent monographs . For instance, estimates of the number of species in the orchid genus Pleurothallis range from 1,120 to 2,500. Genera from some other groups of vascular plants (like pteridophytes ), which have similarly large numbers of species, include Selaginella , Asplenium and Cyathea . Petal Although petals are usually
1120-571: The genus, and it can alternatively be treated in the broad sense. The most common uses of Ranunculus species in traditional medicines are as an antirheumatic , as a rubefacient , and to treat intermittent fever . The findings in some Ranunculus species of, for example, protoanemonin , anemonin , may justify the uses of these species against fever, rheumatism and rubefacient in Asian traditional medicines. All Ranunculus (buttercup) species are poisonous when eaten fresh, but their acrid taste and
1160-484: The late Eocene or Oligocene and rapidly radiated up to the present, dispersing worldwide. Fossil evidence suggests that despite no longer occurring there, they inhabited Antarctica up to the mid-late Pliocene , even while glaciations were rapidly altering the landscape. Ranunculus gailensis and Ranunculus tanaiticus seed fossils have been described from the Pliocene Borsoni Formation in
1200-538: The legend, Coyote was tossing his eyes up in the air and catching them again when Eagle snatched them. Unable to see, Coyote made eyes from the buttercup. Molecular investigation of the genus has revealed that Ranunculus is not monophyletic with respect to a number of other recognized genera in the family—e.g. Ceratocephala , Halerpestes , Hamadryas , Laccopetalum , Myosurus , Oxygraphis , Paroxygraphis and Trautvetteria . A proposal to split Ranunculus into several genera has thus been published in
1240-427: The mechanism on their petals to change colour in acting as a communicative mechanism for the bird to visit. An example is the tree fuchsia ( Fuchsia excorticata ), which are green when needing to be pollinated and turn red for the birds to stop coming and pollinating the flower. Flowers can be pollinated by short-tailed bats. An example of this is the dactylanthus ( Dactylanthus taylorii ). This plant has its home under
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1280-411: The mechanisms to form petals evolved very few times (perhaps only once), rather than evolving repeatedly from stamens. Pollination is an important step in the sexual reproduction of higher plants. Pollen is produced by the male flower or 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
1320-487: The most conspicuous parts of animal-pollinated flowers, wind-pollinated species, such as the grasses , either have very small petals or lack them entirely (apetalous). The collection of all petals in a flower is referred to as the corolla. 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 petals, without fusion of individual segments,
1360-713: The number of species. For instance, the occurrence of apomixis allows the recognition of large numbers of agamospecies , and such taxa have helped to bolster genera such as Ranunculus and Potentilla . The introduction of infrageneric taxa (such as the subgenus , section and series ) in the 19th century by botanists including Augustin Pyrame de Candolle allowed the retention of large genera that would otherwise have become unwieldy. E. J. H. Corner believed that studying large genera might enable greater insights into evolutionary biology , and he concentrated his efforts on large tropical genera such as Ficus . According to
1400-531: The petals in aiding the pollinator towards the nectar. Pollinators have the ability to determine specific flowers they wish to pollinate. 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 (unless incentives are not consistently met and competition prevails). The petals could produce different scents to allure desirable pollinators or repel undesirable pollinators. Some flowers will also mimic
1440-424: The plants are growing as opportunistic colonizers, as in the case of garden weeds. The water crowfoots ( Ranunculus subgenus Batrachium ), which grow in still or running water, are sometimes treated in a separate genus Batrachium (from Greek βάτραχος bátrakhos , "frog"). They have two different leaf types, thread-like leaves underwater and broader floating leaves. In some species, such as R. aquatilis ,
1480-399: The pollen scattered by the wind tends to not reach other flowers. Flowers have various regulatory mechanisms to attract insects. One such helpful mechanism is the use of colour guiding marks. Insects such as the bee or butterfly can see the ultraviolet marks which are contained on these flowers, acting as an attractive mechanism which is not visible towards the human eye. Many flowers contain
1520-420: The same or nearby flowers. However, pollinators are rather selective in determining the flowers they choose to pollinate. This develops competition between flowers and as a result flowers must provide incentives to appeal to pollinators (unless the flower self-pollinates or is involved in wind pollination). Petals play a major role in competing to attract pollinators. Henceforth pollination dispersal could occur and
1560-407: 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 can change the colour of their petals as a signal to mutual pollinators to approach or keep away. Furthermore, the shape and size of
1600-414: The survival of many species of flowers could prolong. Petals have various functions and 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
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