Magnoliophyta (flowering plants) Fossil range: Early Cretaceous - Recent
Magnolia virginiana Sweet Bay
Scientific classification
Kingdom: Plantae Division: Magnoliophyta
Classes
Magnoliopsida - Dicots Liliopsida - Monocots

The flowering plants or angiosperms are the most widespread group of land plants. The Early Cretaceous ( timestratigraphic name or the Lower Cretaceous ( logstratigraphic name is the earlier of the two major divisions of the Cretaceous The Sweetbay magnolia ( Magnolia virginiana) also called just Sweetbay is a member of the Magnolia family Magnoliaceae. Plants are living Organisms belonging to the kingdom Plantae. A class is the Taxonomic rank in the Biological classification of organisms in Biology below phylum and above order. Dicotyledons, or "dicots", is a name for a group of Flowering plants whose Seed typically has two embryonic leaves or Cotyledons There Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons The embryophytes are the most familiar group of Plants They include Trees Flowers Ferns Mosses and various other green The flowering plants and the gymnosperms comprise the two extant groups of seed plants. Gymnosperm (Gymnospermae are a group of Spermatophyte seed-bearing Plants with Ovules on the edge or blade of an open Sporophyll, which are The spermatophytes (from the Greek word "Σπερματόφυτα" (also known as phanerogams) comprise those Plants that produce Seeds They are The flowering plants are distinguished from other seed plants by a series of apomorphies, or derived characteristics. Cladistics is the hierarchical classification of Species based on evolutionary ancestry A trait is a distinct phenotypic character of an organism that may be inherited environmentally determined or somewhere in between

Contents 1 Angiosperm derived characteristics 2 Evolution 3 Classification 3.1 History of classification 4 Flowering plant diversity 5 Vascular anatomy 6 The flower, fruit, and seed 6.1 Flowers 6.2 Fertilization and embryogenesis 6.3 Fruit and seed 7 Economic importance 8 See also 9 References 10 External links

Angiosperm derived characteristics

• Flowers

The flowers of flowering plants are the most remarkable feature distinguishing them from other seed plants. A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also Flowers aided angiosperms by enabling a wider range of evolutionary relationships and broadening the ecological niches open to them, allowing flowering plants to eventually dominate terrestrial ecosystems. In Ecology, a niche (pronounced nich nēsh or nish A shorthand definition of niche is how an organism makes a living An ecoregion ( ecological region) sometimes called a bioregion, is an ecologically and geographically defined area smaller than a "realm" or "

• Stamens with two pairs of pollen sacs

Stamens are much lighter than the corresponding organs of gymnosperms and have contributed to the diversification of angiosperms through time with adaptations to specialized pollination syndromes, such as particular pollinators. The stamen ( Plural stamina or stamens, from Latin stamen meaning "thread of the warp " is the male An adaptation is a characteristic of an Organism that has been favored by Natural selection and Pollination in angiosperms and Gymnosperms is the process that transfers pollen grains, which contain the male Gametes (sperm to where the female Stamens have also become modified through time to prevent self-fertilization, which has permitted further diversification, allowing angiosperms to eventually fill more niches. Reproduction is the Biological process by which new individual Organisms are produced

• Reduced male parts, three cells

The male gametophyte in angiosperms is significantly reduced in size compared to those of gymnosperm seed plants. In Plants and Algae that undergo Alternation of generations, a gametophyte is the multicellular structure or phase that is Haploid, containing The smaller pollen decreases the time from pollination – the pollen grain reaching the female plant – to fertilization of the ovary; in gymnosperms fertilization can occur up to a year after pollination, while in angiosperms the fertilization begins very soon after pollination. For soil improvement see Fertilization (soil. The shorter time leads to angiosperm plants setting seeds sooner and faster than gymnosperms, which is a distinct evolutionary advantage.

• Closed carpel enclosing the ovules (carpel or carpels and accessory parts may become the fruit)

The closed carpel of angiosperms also allows adaptations to specialized pollination syndromes and controls to prevent self-fertilization, thereby maintaining increased diversity. A gynoecium (from Ancient Greek gyne, "woman" is the Female reproductive part of a Flower. The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. Once the ovary is fertilized the carpel and some surrounding tissues develop into a fruit, another opportunity for angiosperms to increase their domination of the terrestrial ecosystem with evolutionary adaptations to dispersal mechanisms. Biological dispersal refers to those processes by which a Species maintains ecosystem

• Reduced female gametophyte, seven cells with eight nuclei

The reduced female gametophyte, like the reduced male gametophyte may be adaptations allowing for more rapid seed set, eventually leading to such flowering plant adaptations as annual herbaceous life cycles, allowing the flowering plants to fill even more niches.

• Endosperm

Endosperm formation generally begins after fertilization and before the first division of the zygote. Endosperm is the tissue produced in the Seeds of most Flowering plants around the time of fertilization For other meanings see Zygote (disambiguation. A zygote (from Greek ζυγωτός zugōtos "joined" or "yoked" Endosperm is a highly nutritive tissue that can provide food for the developing embryo, the cotyledons, and sometimes for the seedling when it first appears. An embryo (from Greek:, plural, lit "that which grows" from en- "in" + bryein "to swell be full" is a multicellular A seedling is a young plant Sporophyte developing out of a plant embryo from a Seed.

These distinguishing characteristics taken together have made the angiosperms the most diverse and numerous land plants and the most commercially important group to humans. The major exception to the dominance of terrestrial ecosystems by flowering plants is the coniferous forest. Temperate coniferous forest is a terrestrial Biome found in temperate regions of the world with warm summers and cool winters and adequate rainfall to sustain a forest

Evolution

Further information: Evolutionary history of plants#Flowers

Land plants have existed for about 425 million years. Early land plants reproduced by spores like their aquatic counterparts. Plant sexuality covers the wide variety of Sexual reproduction systems found across the Plant kingdom In Biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions Aquatic plants &mdash also called hydrophytic plants or hydrophytes &mdash are plants that have adapted to living in or on aquatic environments Marine organisms can easily scatter copies of themselves to float away and grow elsewhere. Marine biology is the scientific study of living Organisms in the Ocean or other marine or Brackish bodies of water Land plants soon found it advantageous to protect their copies from drying out and other hazards by enclosing them in a case, the seed. A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored Early seed bearing plants, like the ginkgo, and conifers (such as pines and firs), did not produce flowers. Ginkgo is a genus of highly unusual non-flowering plants with one extant species G This article is about the tree For other uses of the term "pine" see Pine (disambiguation. Firs ( Abies) are a genus of between 45-55 species of Evergreen conifers in the family Pinaceae.

The earliest fossil of an angiosperm, or flowering plant, Archaefructus liaoningensis, is dated to about 125 million years BP[1]. FOSSIL is a standard protocol for allowing serial communication for Telecommunications programs under the DOS Operating system. Archaefructus is an extinct genus of Herbaceous aquatic Seed plants with two known species Pollen, considered directly linked to flower development, has been found in the fossil record perhaps as long ago as 130 million years.

While there is only hard evidence of such flowers existing about 130 million years ago, there is some circumstantial evidence that they may have existed 250 million years ago. A chemical used by plants to defend their flowers, oleanane, has been detected in fossil plants that old, including gigantopterids[2], which evolved at that time and bear many of the traits of modern, flowering plants, though they are not known to be flowering plants themselves, because only their stems and prickles have been found preserved in detail, one of the earliest examples of petrification. Oleananes is the name given to chemicals produced by many Flowering plants which have a suppressing effect on some insect pest organisms. Gigantopterids ( Gigantopteridales) is the name given to Fossils of a group of plants existing in the Late Permian, until some 250 million years ago Petrified wood (from the Greek root "petro" meaning "rock" or "stone" literally "wood turned into stone" is a type of Fossil: it

The apparently sudden appearance of relatively modern flowers in the fossil record posed such a problem for the theory of evolution that it was called an "abominable mystery" by Charles Darwin. eVolution is the third Album by eLDee, it was due to be released in 2008 Charles Robert Darwin (February 12 1809 &ndash April 19 1882 was an English naturalist, who realised and demonstrated that all Species of life ^[1] However the fossil record has grown since the time of Darwin, and recently discovered angiosperm fossils such as Archaefructus, along with further discoveries of fossil gymnosperms, suggest how angiosperm characteristics may have been acquired in a series of steps. Several groups of extinct gymnosperms, particularly seed ferns, have been proposed as the ancestors of flowering plants but there is no continuous fossil evidence showing exactly how flowers evolved. Pteridospermatophyta, also called seed ferns, is an extinct Spermatophyte group of the Plantae kingdom. In Genetics, the most recent common ancestor ( MRCA) of any set of Organisms is the most recent individual from which all organisms in the group are directly Some older fossils, such as the upper Triassic Sanmiguelia, have been suggested. The Triassic is a geologic period and system that extends from about 251 to 199 Ma (million years ago Based on current evidence, some propose that the ancestors of the angiosperms diverged from an unknown group of gymnosperms during the late Triassic (245-202 million years ago). The Triassic is a geologic period and system that extends from about 251 to 199 Ma (million years ago The relationship of the earlier gigantopterids to flowering plants is still enigmatic. Gigantopterids ( Gigantopteridales) is the name given to Fossils of a group of plants existing in the Late Permian, until some 250 million years ago

A close relationship between Angiosperms and Gnetophytes, suggested on the basis of morphological evidence, has been disputed on the basis of molecular evidence that suggest Gnetophytes are more closely related to other gymnosperms. The Plant division Gnetophyta or gnetophytes comprise three related families of Woody plants grouped in the Gymnosperms The gnetophytes differ from The term morphology in Biology refers to the outward appearance ( Shape, Structure, Colour, Pattern) of an Organism Molecular biology is the study of Biology at a molecular level Gymnosperm (Gymnospermae are a group of Spermatophyte seed-bearing Plants with Ovules on the edge or blade of an open Sporophyll, which are

Recent DNA analysis (molecular systematics) [3] [4] show that Amborella trichopoda, found on the Pacific island of New Caledonia, belongs to a sister group of the other flowering plants, and morphological studies [5] suggest that it has features which may have been characteristic of the earliest flowering plants. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Amborella trichopoda is a rare vesselless understory Shrub or small Tree found only on the island of New Caledonia. For the former North American fur-trading district see New Caledonia (Canada, and for the Scottish colony in Panama see Darien scheme. Cladistics is the hierarchical classification of Species based on evolutionary ancestry

The great angiosperm radiation, when a great diversity of angiosperms appear in the fossil record, occurred in the mid-Cretaceous (approximately 100 million years ago). An adaptive radiation is a rapid Evolutionary radiation characterized by an increase in the morphological and ecological diversity of a single rapidly diversifying lineage The Cretaceous (kriːˈteɪʃəs, usually abbreviated 'K' for its German translation "Kreide" is a geologic period and system, reaching from the end of However, a study in 2007 estimated that the division of the five most recent (the genus Ceratophyllum, the family Chloranthaceae, the eudicots, the magnoliids, and the monocots) of the eight main groups occurred around 140 million years ago. Ceratophyllum is a Cosmopolitan genus of Flowering plants commonly found in ponds marshes and quiet streams in tropical and in temperate regions Chloranthaceae is the Botanical name of a family of Flowering plants. Eudicots and Eudicotyledons are terms introduced by Doyle & Hotton (1991 to refer to a group of Flowering plants that had been called "tricolpates" or "non-Magnoliid Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons [6] By the late Cretaceous, angiosperms appear to have become the predominant group of land plants, and many fossil plants recognizable as belonging to modern families (including beech, oak, maple, and magnolia) appeared. For the babyfood see Beech-Nut. Beech ( Fagus) is a genus of ten Species of Deciduous Trees in the The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin Acer ( maple) is a Genus of Trees or Shrubs They are variously classified in a family of their own the Aceraceae, or Magnolia is a large Genus of about 210 Flowering plant Species in the subclass Magnolioideae of the family

However, some authors have proposed an earlier origin for angiosperms, sometime in the Paleozoic (251 million years ago or more). The Paleozoic or Palaeozoic Era (from the Greek palaio (παλαιο "old" and zoe (ζωη "life" meaning "ancient life" ^[2][3][4]

It is generally assumed that the function of flowers, from the start, was to involve mobile animals in their reproduction processes. Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea A function is part of an answer to a question about why some object or process occurred in a system that Evolved through a process of Selection. Reproduction is the Biological process by which new individual Organisms are produced Pollen can be scattered without bright colors and obvious shapes. Expending energy on these structures would appear to be a liability, unless they provide significant benefit. In Physics and other Sciences energy (from the Greek grc ἐνέργεια - Energeia, "activity operation" from grc ἐνεργός

Island genetics provides one proposed explanation for the sudden, fully developed appearance of flowering plants. Populations with small population size behave differently to larger populations Island genetics is believed to be a common source of speciation in general, especially when it comes to radical adaptations which seem to have required inferior transitional forms. Speciation is the Evolutionary process by which new biological Species arise Flowering plants may have evolved in an isolated setting like an island or island chain, where the plants bearing them were able to develop a highly specialized relationship with some specific animal (a wasp, for example). An island (ˈaɪlənd or isle (/ˈaɪl/ is any piece of land that is completely surrounded by water in two dimensions above high tide and isolated from other significant A wasp is any Insect of the order Hymenoptera and suborder Apocrita that is neither a Bee nor Ant. Such a relationship, with a hypothetical wasp carrying pollen from one plant to another much the way fig wasps do today, could result in both the plant(s) and their partners developing a high degree of specialization. Fig wasps are Wasps of the family Agaonidae which pollinate Figs or are otherwise associated with figs A generalist species is able to thrive in a wide variety of environmental conditions and can make use of a variety of different resources (for example a Heterotroph Note that the wasp example is not incidental; bees, which apparently evolved specifically due to mutualistic plant relationships, are descended from wasps. Bees are flying Insects closely related to Wasps and Ants Bees are a Monophyletic lineage within the superfamily Apoidea

Animals are also involved in the distribution of seeds. Fruit, which is formed by the enlargement flower parts, is frequently a seed disbursal tool which depends upon animals, who eat or otherwise disturb it, incidentally scattering the seeds it contains (see frugivory). The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. A frugivore is an Animal that feeds primarily or in some cases exclusively on Fruit. While many such mutualistic relationships remain too fragile to survive competition with mainland animals and spread, flowers proved to be an unusually effective means of production, spreading (whatever their actual origin) to become the dominant form of land plant life. Mutualism is a Biological interaction between individuals of two different Species, where both individuals derive a fitness benefit for example increased Competition can be defined as an interaction between Organisms or Species, in which the fitness of one is lowered by the presence of another

Flowers are derived from leaf and stem components, arising from a combination of genes normally responsible for forming new shoots. In Botany, a leaf is an above-ground Plant organ specialized for Photosynthesis. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance [7] The most primitive flowers are thought to have had a variable number of flower parts, often separate from (but in contact with) each other. The flowers would have tended to grow in a spiral pattern, to be bisexual (in plants, this means both male and female parts on the same flower), and to be dominated by the ovary (female part). In the Flowering plants an ovary is a part of the female reproductive organ of the flower or Gynoecium. As flowers grew more advanced, some variations developed parts fused together, with a much more specific number and design, and with either specific sexes per flower or plant, or at least "ovary inferior".

Flower evolution continues to the present day; modern flowers have been so profoundly influenced by humans that some of them cannot be pollinated in nature. Many modern, domesticated flowers used to be simple weeds, which only sprouted when the ground was disturbed. Some of them tended to grow with human crops, perhaps already having symbiotic companion plant relationships with them, and the prettiest did not get plucked because of their beauty, developing a dependence upon and special adaptation to human affection. Companion planting in gardening and agriculture is planting of different crops in close physical proximity on the theory that they will help each other [8]

Classification

There are eight groups of living angiosperms:

• Amborella - a single species of shrub from New Caledonia
• Nymphaeales - about 80 species^[5] - water lilies and Hydatellaceae
• Austrobaileyales - about 100 species^[5] of woody plants from various parts of the world
• Chloranthales - several dozen species of aromatic plants with toothed leaves
• Ceratophyllum - about 6 species^[5] of aquatic plants, perhaps most familiar as aquarium plants
• magnoliids - about 9,000 species,^[5] characterized by trimerous flowers, pollen with one pore, and usually branching-veined leaves - for example magnolias, bay laurel, and black pepper
• eudicots - about 175,000 species,^[5] characterized by 4- or 5- merous flowers, pollen with three pores, and usually branching-veined leaves - for example sunflowers, petunia, buttercup, apples and oaks
• monocots - about 70,000 species,^[5] characterized by trimerous flowers, a single cotyledon, pollen with one pore, and usually parallel-veined leaves - for example grasses, orchids, and palms

The exact relationship between these eight groups is not yet clear, although it has been determined that the first three groups to diverge from the ancestral angiosperm were Amborellales, Nymphaeales, and Austrobaileyales, in that order. Amborella trichopoda is a rare vesselless understory Shrub or small Tree found only on the island of New Caledonia. For the former North American fur-trading district see New Caledonia (Canada, and for the Scottish colony in Panama see Darien scheme. Nymphaeales is a Botanical name at the rank of order. When recognized it includes water lilies and sometimes other Aquatic plants This Nymphaeaceae is a family of Flowering plants Members of this family are commonly called water lilies and live in freshwater areas in temperate and tropical climates Hydatellaceae is the Botanical name for a family of Flowering plants containing the genus Trithuria, which has been recently re-classified to Austrobaileyales is the Botanical name for an order of Flowering plants, consisting of about 100 species of Woody plants perhaps the most famous of A woody plant is any vascular Plant that has a perennial stem that is above ground and covered by a layer of thickened Bark. Chloranthaceae is the Botanical name of a family of Flowering plants. Ceratophyllum is a Cosmopolitan genus of Flowering plants commonly found in ponds marshes and quiet streams in tropical and in temperate regions A sepal (from Latin separatus "separate" + petalum "petal" is a part of the flower of Angiosperms or flower plants Magnolia is a large Genus of about 210 Flowering plant Species in the subclass Magnolioideae of the family The Bay Laurel ( Laurus nobilis, Lauraceae) also known as True Laurel, Sweet Bay, Grecian Laurel, Laurel, or Black pepper ( Piper nigrum) is a flowering Vine in the family Piperaceae, cultivated for its Fruit, which is usually dried Eudicots and Eudicotyledons are terms introduced by Doyle & Hotton (1991 to refer to a group of Flowering plants that had been called "tricolpates" or "non-Magnoliid The sunflower ( Helianthus annuus) is an Annual plant in the family Asteraceae and native to the Americas, with a large flowering For Petunia Pig, a Looney Tunes character see Petunia Pig For Aunt Petunia see Aunt Petunia For The apple is the pomaceous Fruit of the apple tree Species Malus domestica in the Rose family Rosaceae. The term oak can be used as part of the common name of any of about 400 species of Trees and Shrubs in the Genus Quercus (from Latin Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons A cotyledon ("seed leaf" from Greek: κοτυληδών kotylēdōn, from κοτύλη ''kotýlē'', "cup bowl" Poaceae or Gramineae is a family in the Class Liliopsida of the flowering plants. Arecaceae or Palmae (also known by the name Palmaceae, which is taxonomically invalid or commonly palm tree) the palm family is a family of Flowering Nymphaeales is a Botanical name at the rank of order. When recognized it includes water lilies and sometimes other Aquatic plants This Austrobaileyales is the Botanical name for an order of Flowering plants, consisting of about 100 species of Woody plants perhaps the most famous of ^[6]

History of classification

The botanical term "Angiosperm", from the ancient Greek αγγειον (receptacle) and σπερμα (seed), was coined in the form Angiospermae by Paul Hermann in 1690, as the name of that one of his primary divisions of the plant kingdom. The Ancient Greek language is the historical stage in the development of the Hellenic language family spanning the Archaic (c Paul Hermann (1646—1695 German born botanist that made the Leiden Botanical Garden in Holland famous In biological Taxonomy, a kingdom or regnum is a Taxonomic rank in either (historically the highest rank or (in the new three-domain system This included flowering plants possessing seeds enclosed in capsules, distinguished from his Gymnospermae, or flowering plants with achenial or schizo-carpic fruits, the whole fruit or each of its pieces being here regarded as a seed and naked. An achene is a type of simple dry Fruit produced by many species of Flowering plants Achenes are "monocarpellate" (formed from one Carpel The term and its antonym were maintained by Carolus Linnaeus with the same sense, but with restricted application, in the names of the orders of his class Didynamia. Carl Linnaeus (Latinized as Carolus Linnaeus, also known after his ennoblement as, May 23 new style (13 May old style 1707 who laid the foundations for Its use with any approach to its modern scope only became possible after 1827, when Robert Brown established the existence of truly naked ovules in the Cycadeae and Coniferae, and applied to them the name Gymnosperms. Year 1827 ( MDCCCXXVII) was a Common year starting on Monday (link will display the full calendar of the Gregorian Calendar (or a Common Robert Brown FRS ( 21 December, 1773 &ndash 10 June, 1858) was a Scottish scientist who is acknowledged as the leading botanist Cycads are a group of Seed plants characterized by a large crown of compound leaves and a stout trunk. From that time onwards, so long as these Gymnosperms were, as was usual, reckoned as dicotyledonous flowering plants, the term Angiosperm was used antithetically by botanical writers, with varying scope, as a group-name for other dicotyledonous plants.

In 1851, Hofmeister discovered the changes occurring in the embryo-sac of flowering plants, and determined the correct relationships of these to the Cryptogamia. 1851 ( MDCCCLI) was a Common year starting on Wednesday (link will display the full calendar of the Gregorian Calendar (or a Common year Wilhelm Friedrich Benedikt Hofmeister ( 18 May 1824 to 12 January 1877) was a German Biologist and Botanist Vascular plants (also known as tracheophytes or higher plants) are those Plants that have lignified tissues for conducting This fixed the position of Gymnosperms as a class distinct from Dicotyledons, and the term Angiosperm then gradually came to be accepted as the suitable designation for the whole of the flowering plants other than Gymnosperms, including the classes of Dicotyledons and Monocotyledons. This is the sense in which the term is used today.

In most taxonomies, the flowering plants are treated as a coherent group. The most popular descriptive name has been Angiospermae (Angiosperms), with Anthophyta ("flowering plants") a second choice. These names are not linked to any rank. The Wettstein system and the Engler system use the name Angiospermae, at the assigned rank of subdivision. A system of plant taxonomy, the Wettstein system recognised the following main groups according to I One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler. The Reveal system treated flowering plants as subdivision Magnoliophytina (Frohne & U. A modern system of plant taxonomy, the Reveal system of plant classification was drawn up by the botanist J Jensen ex Reveal, Phytologia 79: 70 1996), but later split it to Magnoliopsida, Liliopsida and Rosopsida. The Takhtajan system and Cronquist system treat this group at the rank of division, leading to the name Magnoliophyta (from the family name Magnoliaceae). A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950's onwards A system of plant taxonomy, the Cronquist system is a scheme for the classification of flowering plants (or Angiosperms) The Dahlgren system and Thorne system (1992) treat this group at the rank of class, leading to the name Magnoliopsida. One of the modern systems of plant taxonomy, the Dahlgren system was published by monocot specialist Rolf Dahlgren. A modern system of plant taxonomy, the Thorne system (1992 of plant classification was drawn up by the botanist Robert F However, the APG system, of 1998, and the APG II system, of 2003^[7], do not treat it as a formal taxon but rather treat it as a clade without a formal botanical name and use the name angiosperms for this clade. A botanical name is a formal scientific name conforming to the International Code of Botanical Nomenclature (ICBN and if the plant is a Cultigen, the

The internal classification of this group has undergone considerable revision. The Cronquist system, proposed by Arthur Cronquist in 1968 and published in its full form in 1981, is still widely used, but is no longer believed to accurately reflect phylogeny. A system of plant taxonomy, the Cronquist system is a scheme for the classification of flowering plants (or Angiosperms) Arthur John Cronquist (1919&ndash1992 was a North American botanist and a specialist on Compositae. Year 1968 ( MCMLXVIII) was a Leap year starting on Monday (link will display full calendar of the Gregorian calendar. Year 1981 ( MCMLXXXI) was a Common year starting on Thursday (link displays the 1981 A general consensus about how the flowering plants should be arranged has recently begun to emerge, through the work of the Angiosperm Phylogeny Group, who published an influential reclassification of the angiosperms in 1998. The Angiosperm Phylogeny Group, or APG, refers to two international groups of systematic botanists who came together to try to establish a consensus view of the Year 1998 ( MCMXCVIII) was a Common year starting on Thursday (link will display full 1998 Gregorian calendar) An update incorporating more recent research was published as APG II^[7] in 2003. Year 2003 ( MMIII) was a Common year starting on Wednesday of the Gregorian calendar.

Traditionally, the flowering plants are divided into two groups, which in the Cronquist system are called Magnoliopsida (at the rank of class, formed from the family name Magnoliacae) and Liliopsida (at the rank of class, formed from the family name Liliaceae). The Liliaceae, or the lily family, is a family of Monocotyledons in the order Liliales. Other descriptive names allowed by Article 16 of the ICBN include Dicotyledones or Dicotyledoneae, and Monocotyledones or Monocotyledoneae, which have a long history of use. The International Code of Botanical Nomenclature ( ICBN) is the set of rules and recommendations dealing with the formal Botanical names that are given to Dicotyledons, or "dicots", is a name for a group of Flowering plants whose Seed typically has two embryonic leaves or Cotyledons There Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons In English a member of either group may be called a dicotyledon (plural dicotyledons) and monocotyledon (plural monocotyledons), or abbreviated, as dicot (plural dicots) and monocot (plural monocots). Dicotyledons, or "dicots", is a name for a group of Flowering plants whose Seed typically has two embryonic leaves or Cotyledons There Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons These names derive from the observation that the dicots most often have two cotyledons, or embryonic leaves, within each seed. A cotyledon ("seed leaf" from Greek: κοτυληδών kotylēdōn, from κοτύλη ''kotýlē'', "cup bowl" The monocots usually have only one, but the rule is not absolute either way. From a diagnostic point of view the number of cotyledons is neither a particularly handy nor reliable character.

Recent studies, as by the APG, show that the monocots form holophyletic or monophyletic group; this clade is given the name monocots. A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor A clade is a taxonomic group comprising a single Common ancestor and all the descendants of that ancestor Monocotyledons or monocots are one of two major groups of Flowering plants (angiosperms that are traditionally recognised the other being Dicotyledons However, the dicots are not (they are a paraphyletic group). In Phylogenetics, a group of organisms is said to be paraphyletic if the group contains its most recent common ancestor but does not contain all Nevertheless, within the dicots a monophyletic group does exist, called the eudicots or tricolpates, and including most of the dicots. Eudicots and Eudicotyledons are terms introduced by Doyle & Hotton (1991 to refer to a group of Flowering plants that had been called "tricolpates" or "non-Magnoliid Eudicots and Eudicotyledons are terms introduced by Doyle & Hotton (1991 to refer to a group of Flowering plants that had been called "tricolpates" or "non-Magnoliid The name tricolpates derives from a type of pollen found widely within this group. Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains) which produce the male Gametes (sperm cells of The name eudicots is formed combining dicot with the prefix eu- (from Greek, for "well," or "good," botanically indicating "true"), as the eudicots share the characters traditionally attributed to the dicots, such as flowers with four or five parts (four or five petals, four or five sepals). A petal (from Ancient Greek petalon "leaf" "thin plate" regarded as a highly modified leaf is one member or part of the corolla A sepal (from Latin separatus "separate" + petalum "petal" is a part of the flower of Angiosperms or flower plants Separating this group of eudicots from the rest of the (former) dicots leaves a remainder, which sometimes are called informally palaeodicots (Greek prefix "palaeo-" means "old"). Paleodicots (sometimes spelled "palaeodicots" is an informal name used by botanists (Spichiger & Savolainen 1997 Leitch et al As this remnant group is not monophyletic this is a term of convenience only.

Flowering plant diversity

The number of species of flowering plants is estimated to be in the range of 250,000 to 400,000. In Biology, a species is one of the basic units of Biological classification and a Taxonomic rank. ^{[8] [9] [10]} The number of families in APG (1998) was 462. In Biological classification, family ( Latin In APG II^[7] (2003) it is not settled; at maximum it is 457, but within this number there are 55 optional segregates, so that the minimum number of families in this system is 402.

The diversity of flowering plants is not evenly distributed. Nearly all species belong to the eudicot (75%), monocot (23%) and magnoliid (2%) clades. The remaining 5 clades contain a little over 250 species in total, i. e. less than 0. 1% of flowering plant diversity, divided among 9 families.

The most diverse families of flowering plants, in their APG circumscriptions, in order of number of species, are:

In the list above (showing only the 10 largest families), the Orchidaceae, Poaceae, Cyperaceae and Araceae are monocot families; the others are dicot families. The family Asteraceae or Compositae (known as the aster, daisy, or sunflower family) is the largest family of Flowering Fabaceae or Leguminosae is a large and economically important family of Flowering plants which is commonly known as the legume family, pea A pea (inaccurately called a '''sweet pea''' by food distubutors is most commonly the small spherical Seed or the seed-pod of the Legume Pisum Rubiaceae is a family of Flowering plants variously called the Madder family, Bedstraw family or coffee Madder is the common name of the Plant genus Rubia, the type genus of the madder family Rubiaceae. Poaceae or Gramineae is a family in the Class Liliopsida of the flowering plants. Grass is the common word that generally describes Monocotyledonous green Plants The family Gramineae ( Poaceae) are the "true grasses" and include Lamiaceae or Labiatae, also known as the mint family is a family of Plants comprising about 210 genera and some 3500 species Mentha ( mint) is a Genus of about 25 Species (and many hundreds of varieties) of Flowering plants in the family The Spurge family ( Euphorbiaceae) is a large family of Flowering plants with 300 genera and around 7500 species Euphorbia is a Genus of Plants belonging to the family Euphorbiaceae. The family Cyperaceae, or the sedges, is a taxon of monocot Flowering plants that superficially resemble grasses or rushes The family Cyperaceae, or the sedges, is a taxon of monocot Flowering plants that superficially resemble grasses or rushes Malvaceae, or the mallow family, is a family of Flowering plants containing over 200 genera with close to 2300 species The arums comprise the Family Araceae (including the numerous Aroids subfamily monocotyledonous Flowering plants in which Flowers The arums comprise the Family Araceae (including the numerous Aroids subfamily monocotyledonous Flowering plants in which Flowers

Vascular anatomy

The amount and complexity of tissue-formation in flowering plants exceeds that of Gymnosperms. In general usage complexity often tends to be used to characterize something with many parts in intricate arrangement The vascular bundles of the stem are arranged such that the xylem and phloem form concentric rings. A vascular bundle is a part of the transport system in Vascular plants The transport itself happens in Vascular tissue, which exists in two forms Xylem In Vascular plants xylem is one of the two types of transport tissue Phloem being the other In Vascular plants phloem is the living tissue that carries organic Nutrients (known as photosynthate particularly Sucrose, a sugar to

In the Dicotyledons, the bundles in the very young stem are arranged in an open ring, separating a central pith from an outer cortex. In each bundle, separating the xylem and phloem, is a layer of meristem or active formative tissue known as cambium; by the formation of a layer of cambium between the bundles (interfascicular cambium) a complete ring is formed, and a regular periodical increase in thickness results from the development of xylem on the inside and phloem on the outside. The soft phloem becomes crushed, but the hard wood persists and forms the bulk of the stem and branches of the woody perennial. Owing to differences in the character of the elements produced at the beginning and end of the season, the wood is marked out in transverse section into concentric rings, one for each season of growth, called annual rings. A season is one of the major divisions of the Year, generally based on yearly periodic changes in Weather. Dendrochronology (from Greek grc δένδρον dendron, "tree" grc χρόνος khronos, "time" and grc -λογία

Among the Monocotyledons, the bundles are more numerous in the young stem and are scattered through the ground tissue. They contain no cambium and once formed the stem increases in diameter only in exceptional cases.

The flower, fruit, and seed

Flowers

Main articles: Flower and Plant sexuality

The characteristic feature of angiosperms is the flower. A flower, also known as a bloom or Blossom, is the reproductive structure found in Flowering plants (plants of the division Magnoliophyta, also Plant sexuality covers the wide variety of Sexual reproduction systems found across the Plant kingdom Flowers show remarkable variation in form and elaboration, and provide the most trustworthy external characteristics for establishing relationships among angiosperm species. The function of the flower is to ensure fertilization of the ovule and development of fruit containing seeds. The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. A seed (in some plants referred to as a kernel) is a small embryonic Plant enclosed in a covering called the seed coat usually with some stored The floral apparatus may arise terminally on a shoot or from the axil of a leaf. Occasionally, as in violets, a flower arises singly in the axil of an ordinary foliage-leaf. Viola, commonly called Violets, is a Genus of Flowering plants in the family Violaceae, with around 400-500 species distributed More typically, the flower-bearing portion of the plant is sharply distinguished from the foliage-bearing or vegetative portion, and forms a more or less elaborate branch-system called an inflorescence. An inflorescence is a group or cluster of Flowers arranged on a stem that is composed of a main Branch or a complicated arrangement of branches

The reproductive cells produced by flowers are of two kinds. Microspores which will divide to become pollen grains, are the "male" cells and are borne in the stamens (or microsporophylls). Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains) which produce the male Gametes (sperm cells of The stamen ( Plural stamina or stamens, from Latin stamen meaning "thread of the warp " is the male The "female" cells called megaspores, which will divide to become the egg-cell (megagametogenesis), are contained in the ovule and enclosed in the carpel (or megasporophyll). Megagametogenesis is the development of a Megaspore into an embryo sac which is the Gametophyte - though a highly reduced one - stage in the life cycle of vascular Ovule literally means "small egg." In Seed plants the ovule is the structure that gives rise to and contains the female reproductive cells A gynoecium (from Ancient Greek gyne, "woman" is the Female reproductive part of a Flower.

The flower may consist only of these parts, as in willow, where each flower comprises only a few stamens or two carpels. Willows, sallows and osiers form the Genus Salix, around 400 species of Deciduous Trees and Shrubs found primarily Usually other structures are present and serve to protect the sporophylls and to form an envelope attractive to pollinators. The individual members of these surrounding structures are known as sepals and petals (or tepals in flowers such as Magnolia where sepals and petals are not distinguishable from each other). A sepal (from Latin separatus "separate" + petalum "petal" is a part of the flower of Angiosperms or flower plants A petal (from Ancient Greek petalon "leaf" "thin plate" regarded as a highly modified leaf is one member or part of the corolla Tepals are elements of the Perianth, or outer part of a flower which include the Petals or Sepals The term tepal is usually used when all segments Magnolia is a large Genus of about 210 Flowering plant Species in the subclass Magnolioideae of the family The outer series (calyx of sepals) is usually green and leaf-like, and functions to protect the rest of the flower, especially the bud. The inner series (corolla of petals) is generally white or brightly colored, and is more delicate in structure. It functions to attract insect or bird pollinators. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described Birds ( class Aves) are bipedal endothermic ( Warm-blooded) Vertebrate animals that lay eggs. Attraction is effected by color, scent, and nectar, which may be secreted in some part of the flower. Olfaction (also known as olfactics or smell) refers to the Sense of smell. Nectar is a Sugar -rich liquid produced by plants It is produced either by the Flowers in which it attracts pollinating animals or by extrafloral The characteristics that attract pollinators account for the popularity of flowers and flowering plants among humans.

While the majority of flowers are perfect or hermaphrodite (having both male and female parts in the same flower structure), flowering plants have developed numerous morphological and physiological mechanisms to reduce or prevent self-fertilization. A hermaphrodite is an organism having both male and female reproductive organs Physiology (from Greek grc φύσις physis, "nature origin" and grc -λογία -logia) is the study of the mechanical physical Heteromorphic flowers have short carpels and long stamens, or vice versa, so animal pollinators cannot easily transfer pollen to the pistil (receptive part of the carpel). A pollinator is the biotic agent ( vector) that moves Pollen from the male Anthers of a Flower to the female stigma of a flower to accomplish Homomorphic flowers may employ a biochemical (physiological) mechanism called self-incompatibility to discriminate between self- and non-self pollen grains. Self-incompatibility ( SI) is a general name for several genetic mechanisms in Angiosperms, which prevent Self-fertilization and thus encourage Outcrossing In other species, the male and female parts are morphologically separated, developing on different flowers.

Fertilization and embryogenesis

Main articles: Fertilization and Plant embryogenesis

Double fertilization refers to a process in which two sperm cells fertilize two cells in the ovary. For soil improvement see Fertilization (soil. Plant embryogenesis is the process that produces a plant embryo from a fertilised ovule by asymmetric cell division and the differentiation of undifferentiated cells into tissues and The term sperm is derived from the Greek word (σπέρμα sperma (meaning "seed" and refers to the male reproductive cells. The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called In the Flowering plants an ovary is a part of the female reproductive organ of the flower or Gynoecium. The pollen grain adheres to the stigma of the carpel (female reproductive structure) and grows a pollen tube that penetrates the ovum through a tiny pore called a micropyle. Pollen is a fine to coarse powder consisting of microgametophytes ( pollen grains) which produce the male Gametes (sperm cells of A gynoecium (from Ancient Greek gyne, "woman" is the Female reproductive part of a Flower. The pollen tube of most Seed plants acts as a conduit to transport sperm cells from the Pollen grain, either from the stigma (in Flowering plants An ovum (plural ova) is a Haploid Female reproductive cell or Gamete. Ovule literally means "small egg." In Seed plants the ovule is the structure that gives rise to and contains the female reproductive cells Two sperm cells are released into the ovary through this tube. One of the two sperm cells fertilizes the egg cell, forming a diploid zygote or embryo, also called the ovule. "Haplo" redirects here For the fictional character see The Death Gate Cycle. Ovule literally means "small egg." In Seed plants the ovule is the structure that gives rise to and contains the female reproductive cells The other sperm cell fuses with two haploid polar nuclei in the center of the embryo sac. The resulting cell is triploid (3n). Polyploidy occurs in cells and Organisms when there are more than two homologous sets of Chromosomes. This triploid cell divides through mitosis and forms the endosperm, a nutrient-rich tissue inside the fruit. Mitosis is the process in which a Eukaryotic cell separates the Chromosomes in its Cell nucleus, into two identical sets in two daughter nuclei Tissue is a cellular organizational level intermediate between cells and a complete organism When seed develops without fertilization, the process is known as apomixis.

Fruit and seed

Main articles: Seed and Fruit

As the development of embryo and endosperm proceeds within the embryo-sac, the sac wall enlarges and combines with the nucellus (which is likewise enlarging) and the integument to form the seed-coat. Ovule literally means "small egg." In Seed plants the ovule is the structure that gives rise to and contains the female reproductive cells The Integumentary System is an organ system that protects the body from damage comprising the Skin, Hair, scales, nails, sweat glands and their The ovary wall develops to form the fruit or pericarp, whose form is closely associated with the manner of distribution of the seed. The term fruit has different meanings dependent on context and the term is not synonymous in Food preparation and Biology. A Fruit in Botany refers to a mature ovary. In fleshy fruits the outer often edible layer is the pericarp, which is the tissue that develops

Frequently the influence of fertilization is felt beyond the ovary, and other parts of the flower take part in the formation of the fruit, e. "Ovaria" redirects here This is also a proposed section and a Synonym of Solanum. g. the floral receptacle in the apple, strawberry and others. The apple is the pomaceous Fruit of the apple tree Species Malus domestica in the Rose family Rosaceae. Garden strawberries are a common variety of strawberry cultivated worldwide

The character of the seed-coat bears a definite relation to that of the fruit. They protect the embryo and aid in dissemination; they may also directly promote germination. Among plants with indehiscent fruits, the fruit generally provides protection for of the embryo and secures dissemination. In this case, the seed-coat is only slightly developed. If the fruit is dehiscent and the seed is exposed, the seed-coat is generally well developed, and must discharge the functions otherwise executed by the fruit. Dehiscence is the spontaneous opening at maturity of a plant structure such as a Fruit, Anther, or Sporangium, to release its contents

Economic importance

Agriculture is almost entirely dependent on angiosperms, either directly or indirectly through livestock feed. Agriculture refers to the production of goods through the growing of plants and fungi and the raising of domesticated Animals The study of agriculture Livestock is the term used to refer (singularly or plurally to a Domesticated Animal intentionally reared in an agricultural setting to produce such as Food Of all the families plants, the Poaceae, or grass family, is by far the most important, providing the bulk of all feedstocks (rice, corn (maize), wheat, barley, rye, oats, pearl millet, sugar cane, sorghum). Poaceae or Gramineae is a family in the Class Liliopsida of the flowering plants. Rice is a Cereal foodstuff which forms an important part of the diet of many people worldwide and as such it is a staple food for many Maize (ˈmeɪz ( Zea mays L. ssp mays) known as corn in some countries is a cereal grain domesticated in Mesoamerica Wheat ( Triticum spp is a worldwide cultivated grass from the Levant area of the Middle East. Barley ( Hordeum vulgare) is an annual Cereal Grain, which serves as a major animal Feed crop, with smaller amounts used for Rye ( Secale cereale) is a grass grown extensively as a grain and forage crop Oats redirects here It may mean either the common cereal oat discussed here or any cultivated or wild species of the Genus Avena. Pearl millet ( Pennisetum glaucum) is the most widely grown type of Millet. Sugarcane ( Saccharum) is a genus of 6 to 37 species (depending on taxonomic interpretation of tall perennial grasses (family Poaceae tribe Andropogoneae Sorghum is a genus of numerous species of grasses, some of which are raised for grain and many of which are used as Fodder plants either cultivated or as part The Fabaceae, or legume family, comes in second place. Fabaceae or Leguminosae is a large and economically important family of Flowering plants which is commonly known as the legume family, pea Also of high importance are the Solanaceae, or nightshade family (potatoes, tomatoes, and peppers, among others), the Cucurbitaceae, or gourd family (also including pumpkins and melons), the Brassicaceae, or mustard plant family (including rapeseed and cabbage), and the Apiaceae, or parsley family. The Solanaceae is a family of Flowering plants that contains a number of important agricultural plants as well as many toxic plants The potato is a Starchy Tuberous crop Vegetable from the perennial Solanum tuberosum of the Solanaceae The tomato ( Solanum lycopersicum, syn Lycopersicon lycopersicum) is a herbaceous usually sprawling plant in the Solanaceae or nightshade family Capsicum is a Genus of Plants from the nightshade family ( Solanaceae) native to the Americas, where it was cultivated for thousands Cucurbitaceae is a Plant family commonly known as Melons, gourds or cucurbits and includes crops like Cucumbers This article refers to the Dried fruit shell For the alternative country musical group of a similar name see The Gourds. Pumpkin is a Gourd -like squash of the genus Cucurbita and the family Cucurbitaceae (which also includes gourds Melon is a term used for various members of the Cucurbitaceae family with fleshy fruit Brassicaceae or Cruciferae, also known as the crucifers, the mustard family or cabbage family is a family (the third lowest primary For the prepared condiment see Mustard (condiment. For other uses of the term "mustard" see Mustard. Rapeseed ( Brassica napus) also known as rape, oilseed rape, rapa, rapaseed and (in the case of one particular group of The cabbage ( Brassica oleracea var capitata) is a leafy garden plant of the Family Brassicaceae (or Cruciferae used as a Parsley ( Petroselinum crispum) is a bright Green, biennial Herb, also used as Spice. Many of our fruits come from the Rutaceae, or rue family, and the Rosaceae, or rose family (including apples, pears, cherries, apricots, plums, etc). Rutaceae, commonly known as the Rue or Citrus family is a family of Plants usually placed in the order Sapindales. The Rosaceae or Rose family is a large family of Plants with about 3000-4000 species in 100-160 genera The apple is the pomaceous Fruit of the apple tree Species Malus domestica in the Rose family Rosaceae. A pear is a pomaceous Fruit produced by a tree of Genus Pyrus. This article is about the Cherry berry also classified as fruit for the ornamental tree See Cherry Blossom. The Apricot ( Prunus armeniaca, "Armenian plum" in Latin syn A plum or gage is a stone fruit Tree in the genus Prunus, subgenus Prunus.

In some parts of the world, certain single species assume paramount importance because of their variety of uses, for example the coconut (Cocos nucifera) on Pacific atolls, and the olive (Olea europaea) in the Mediterranean region. The Coconut Palm ( Cocos nucifera) is a member of the Family Arecaceae (palm family An atoll (pronounced /ˈætʌl/ is an island of Coral that encircles a Lagoon partially or completely The Olive ( Olea europaea) is a Species of small Tree in the family Oleaceae, native to the coastal areas of the eastern The Mediterranean Basin refers to the lands around and surrounded by the Mediterranean Sea.

Flowering plants also provide economic resources in the form of wood, paper, fiber (cotton, flax, and hemp, among others), medicines (digitalis, camphor), decorative and landscaping plants, and many other uses. Wood is hard fibrous lignified structural tissue produced as secondary Xylem in the stems of Woody plants notably trees but also shrubs Paper is thin material mainly used for writing upon printing upon or packaging Cotton is a soft staple Fibre that grows around the seeds of the cotton plant ( Gossypium sp Flax (also known as common flax or linseed) (binomial name Linum usitatissimum) is a member of the genus Linum This article is about the cultivation and uses of industrial hemp not its psychoactive cousin Cannabis (drug. } Camphor is a waxy white or transparent solid with a strong aromatic odor The main area in which they are surpassed by other plants is timber production. Lumber or timber is Wood in any of its stages from felling through readiness for use as structural Material for Construction, or

See also

• List of flowers

References

External links

• Angiosperms – Tree of Life Web Project
• Cronquist, Arthur. (1981) An Integrated System of Classification of Flowering Plants. Columbia Univ. Press, New York.
• Dilcher, D. 2000. Toward a new synthesis: Major evolutionary trends in the angiosperm fossil record. PNAS [Proceedings of the National Academy of Sciences of the United States of America] 97: 7030-7036 (available online here)
• Heywood, V. H. , Brummitt, R. K. , Culham, A. & Seberg, O. (2007). Flowering Plant Families of the World. Richmond Hill, Ontario, Canada: Firefly Books. ISBN 1-55407-206-9.  
• Oldest Known Flowering Plants Identified By Genes, William J. Cromie, Harvard Gazette, December 16, 1999. Events 755 - An Lushan revolts against Chancellor Yang Guozhong at Fanyang, initiating the An Shi Rebellion Year 1999 ( MCMXCIX) was a Common year starting on Friday (link will display full 1999 Gregorian calendar)
• L. Watson and M. J. Dallwitz (1992 onwards). The families of flowering plants: descriptions, illustrations, identification, information retrieval.
• Simpson, M. G. Plant Systematics. Elsevier Academic Press. 2006.
• Raven, P. H. , R. F. Evert, S. E. Eichhorn. Biology of Plants, 7th Edition. W. H. Freeman. 2004.

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