Hemerocallis flower, with three flower parts in each whorl

Wheat, an economically important monocot

The monocotyledons or Monocots are a group of flowering plants, (angiosperms) dominating great parts of the earth. Monocots comprise the majority of agricultural plants in terms of biomass produced. There are between 50,000 and 60,000 species within this group; according to IUCN there are 59,300 species.[1] Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... Species , etc The daylily is any of about 15 species of flowering plants in the genus Hemerocallis. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2592 × 1944 pixel, file size: 1. ... Image File history File linksMetadata Size of this preview: 800 × 600 pixel Image in higher resolution (2592 × 1944 pixel, file size: 1. ... Species T. aestivum T. boeoticum T. compactum T. dicoccoides T. dicoccon T. durum T. monococcum T. spelta T. sphaerococcum T. timopheevii References:   ITIS 42236 2002-09-22 For the indie rock group see: Wheat (band). ... It has been suggested that Angiospermae, and Anthophyta be merged into this article or section. ... In biology, a species is one of the basic units of biodiversity. ...

The largest family in this group by number of species (and in the flowering plants) are the orchids (usually taken to be the family Orchidaceae, but sometimes treated at the rank of order), with about twenty thousand species. These have very complex (and striking) flowers, adapted for highly specific insect pollination. Subfamilies Apostasioideae Cypripedioideae Epidendroideae Orchidoideae Vanilloideae For genera, see list of Orchidaceae genera. ... In botanical nomenclature, a taxon is usually assigned to a rank in a hierarchy. ... Orders See taxonomy Insects (Class Insecta) are a major group of arthropods and the most diverse group of animals on the Earth, with over a million described species—more than all other animal groups combined. ... A flower-fly pollinating a Common Daisy (Bellis perennis) Pollination is an important step in the reproduction of seed plants: the transfer of pollen grains (male gametes) to the plant carpel, the structure that contains the ovule (female gamete). ...

The economically most important family in this group (and in the flowering plants) are the grasses, family Poaceae (Gramineae). These include all the true grains (rice, wheat, maize, etc.), the pasture grasses and the bamboos. This family of the true grasses have evolved in another direction, becoming highly specialized for wind pollination. Grasses produce much smaller flowers, which are gathered in highly visible plumes (inflorescences). A further noteworthy, and economically important family is the palm family Arecaceae (Palmae). Subfamilies There are 7 subfamilies: Subfamily Arundinoideae Subfamily Bambusoideae Subfamily Centothecoideae Subfamily Chloridoideae Subfamily Panicoideae Subfamily Pooideae Subfamily Stipoideae The true grasses are monocotyledonous plants (Class Liliopsida) in the Family Poaceae, also known as Gramineae. ... Subfamilies There are 7 subfamilies: Subfamily Arundinoideae Subfamily Bambusoideae Subfamily Centothecoideae Subfamily Chloridoideae Subfamily Panicoideae Subfamily Pooideae Subfamily Stipoideae The true grasses are monocotyledonous plants (Class Liliopsida) in the Family Poaceae, also known as Gramineae. ... An assortment of grains The word grain has a great many meanings, most being descriptive of a small piece or particle. ... Species Oryza glaberrima Oryza sativa The planting of rice is often a labour-intensive process Terrace of rice paddies in Yunnan Province, southern China. ... Species T. aestivum T. boeoticum T. compactum T. dicoccoides T. dicoccon T. durum T. monococcum T. spelta T. sphaerococcum T. timopheevii References:   ITIS 42236 2002-09-22 For the indie rock group see: Wheat (band). ... “Corn” redirects here. ... Diversity Around 91 genera and 1,000 species Subtribes Arthrostylidiinae Arundinariinae Bambusinae Chusqueinae Guaduinae Melocanninae Nastinae Racemobambodinae Shibataeinae See the full Taxonomy of the Bambuseae. ... Red clover inflorescence (spike) An inflorescence is a group or cluster of flowers on a branch of a plant. ... Genera Many; see list of Arecaceae genera Arecaceae (sometimes known by the names Palmae or Palmaceae, although the latter name is taxonomically invalid. ...

Name, characters

The name monocotyledons is derived from the traditional botanical name Monocotyledones, which derives from the fact that most members of this group have one cotyledon, or embryonic leaf, in their seeds. This as opposed to the traditional Dicotyledones, which typically have two cotyledons. From a diagnostic point of view the number of cotyledons is neither a particularly handy (as they are only present for a very short period in a plant's life), nor totally reliable character. This seedling germinated producing two plain-looking cotyledons later followed by two normal-looking leaves that are small copies of the adult leaves. ... A ripe red jalapeño cut open to show the seeds For other uses, see Seed (disambiguation). ... Orders See text. ...

Nevertheless, monocots are a distinctive group.^[1] One of the most noticeable traits is that a monocot's flower is trimerous, with the flower parts in threes or in multiples of three. For example, a monocotyledon's flower typically has three, six, or nine petals. Many monocots also have leaves with parallel veins. “Foliage” redirects here. ...

Hypoxis decumbens L. with a typical monocot perigone and parallel leaf venation

ImageMetadata File history File links Download high resolution version (2048x1536, 683 KB) Summary Hypoxis decumbens (Hypoxidaceae) by J. Ziffer, Santa Catarina, Brazil. ... ImageMetadata File history File links Download high resolution version (2048x1536, 683 KB) Summary Hypoxis decumbens (Hypoxidaceae) by J. Ziffer, Santa Catarina, Brazil. ... Carolus Linnaeus, also known after his ennoblement as  , (May 23, 1707[1] – January 10, 1778), was a Swedish botanist, physician and zoologist[2] who laid the foundations for the modern scheme of nomenclature. ...

Morphology, compared to the (former) dicotyledons

The traditionally listed differences between monocotyledons and dicotyledons are as follows. This is a broad sketch only, not invariably applicable, as there are a number of exceptions. The differences indicated are more true for monocots versus eudicots, as per the APG II system: Orders Base Monocots: Acorus Alismatales Asparagales Dioscoreales Liliales Pandanales Family Petrosaviaceae Commelinids: Arecales Commelinales Poales Zingiberales Family Dasypogonaceae Monocotyledons or monocots are a group of flowering plants usually ranked as a class and once called the Monocotyledoneae. ... In the APG-system, the names eudicots or tricolpates are applied to a monophyletic group that includes most of the (former) dicotyledons. ... A modern system of plant taxonomy, the APG II system of plant classification was published in 2003 by the Angiosperm Phylogeny Group, APG, in Angiosperm Phylogeny Group (2003). ...

Flowers: In monocots, flowers are trimerous (number of flower parts in a whorl in threes) while in dicots the flowers are tetramerous or pentamerous (flower parts are in fours or fives).

Pollen: In monocots, pollen has one furrow or pore while dicots have three. fur·row Pronunciation: f&r-()O, f&-()rO Function: noun Etymology: Middle English furgh, forow, from Old English furh; akin to Old High German furuh furrow, Latin porca 1 a : a trench in the earth made by a plow b : plowed land : FIELD 2 : something that resembles the track of... A pore, in general, is some form of opening, usually very small. ...

Seeds: In monocots, the embryo has one cotyledon while the embryo of the dicot has two. This seedling germinated producing two plain-looking cotyledons later followed by two normal-looking leaves that are small copies of the adult leaves. ...

Stems: In monocots, vascular bundles in the stem are scattered, in dicots arranged in a ring. Cross section of celery stalk, showing vascular bundles, which include both phloem and xylem. ... A stem is the main axis of a vascular plant that is divided into nodes and internodes and has one or more leaves or buds at the nodes. ...

Roots: In monocots, roots are adventitious, while in dicots they develop from the radicle. Adventitious, in botany, refers to structures that develop in an unusual place, and in medicine, it refers to conditions acquired after birth. ... In botany, the radicle is the first part of a seedling (a growing plant embryo) to emerge from the seed during germination. ...

slice of onion, showing parallel veins

Leaves: In monocots, the major leaf veins are parallel, while in dicots they are reticulate. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... In biology, a vein is a blood vessel which carries blood toward the heart. ... Parallel is a term in geometry and in everyday life that refers to a property in Euclidean space of two or more lines or planes, or a combination of these. ...

However, these differences are not hard and fast: some monocots have characteristics more typical of dicots, and vice-versa. This is in part because "dicots" are a paraphyletic group with respect to monocots, and some dicots may be more closely related to monocots than to other dicots. In particular, several early-branching lineages of "dicots" share "monocot" characteristics, suggesting that these are not defining characters of monocots. When monocots are compared to eudicots, the differences are more concrete. Paraphyletic - Wikipedia /**/ @import /skins-1. ... In the APG-system, the names eudicots or tricolpates are applied to a monophyletic group that includes most of the (former) dicotyledons. ...

Taxonomy

The monocots are considered to form a monophyletic group arising early in the history of the flowering plants. The earliest fossils presumed to be monocot remains date from the early Cretaceous period. In phylogenetics, a group is monophyletic (Greek: of one stem) if all organisms in that group are known to have developed from a common ancestral form, and all descendants of that form are included in the group. ... It has been suggested that Angiospermae, and Anthophyta be merged into this article or section. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ...

Taxonomists have considerable latitude in naming this group, as the monocots are a group above the rank of family. Article 16 of the ICBN allows either a descriptive name or a name formed from the name of an included family. The International Code of Botanical Nomenclature is the set of rules according to which plants are given their formal botanical names (scientific names). ... Descriptive botanical names: Art 16 of the ICBN rules that names above the rank of family may be either descriptive or based on the name of an included genus. ...

Grass sprouting on left (a monocot), showing a single cotyledon. Compared to a dicot (right)

Historically, the monocotyledons were named: Image File history File linksMetadata Monocot_vs_dicot_crop_Pengo. ... Image File history File linksMetadata Monocot_vs_dicot_crop_Pengo. ...

• Monocotyledoneae in the de Candolle system and the Engler system.
• Monocotyledones in the Bentham & Hooker system and the Wettstein system
• class Liliopsida in the Takhtajan system and the Cronquist system.
• subclass Liliidae in the Dahlgren system and the Thorne system (1992).
• clade monocots in the APG system and the APG II system.

Each of the systems mentioned above use their own internal taxonomy for the group. The monocotyledons are famous as a group that is extremely stable in its outer borders (it is a well-defined, coherent group), while in its internal taxonomy is extremely unstable (historically no two authoritative systems have agreed with each other on how the monocotyledons are related to each other). ... An early taxonomic system, the de Candolle system was originally published in : A.P. de Candolle (2nd edition, 1819). ... One of the prime systems of plant taxonomy, the Engler system was devised by Adolf Engler. ... It has been suggested that this article or section be merged into Monocotyledon. ... An early taxonomic system, the Bentham & Hooker system for seed plants was published in : G. Bentham & J.D. Hooker (three volumes, 1862–1883). ... A system of plant taxonomy, the Wettstein system recognised the following main groups, according to R. Wettstein (4th edition, 1935). ... Liliopsida is the botanical name for a class. ... A system of plant taxonomy, the Takhtajan system of plant classification was published by Armen Takhtajan, in several versions from the 1950s onwards. ... A system of plant taxonomy, the Cronquist system is a scheme for the classification of flowering plants (or angiosperms). ... Liliidae is a botanical name at the rank of subclass. ... 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. Thorne (1920- ). He replaced it in 2000 with a new system. ... A clade is a term belonging to the discipline of cladistics. ... Orders Base Monocots: Acorus Alismatales Asparagales Dioscoreales Liliales Pandanales Family Petrosaviaceae Commelinids: Arecales Commelinales Poales Zingiberales Family Dasypogonaceae Monocotyledons or monocots are a group of flowering plants usually ranked as a class and once called the Monocotyledoneae. ... A modern system of plant taxonomy, the APG system of plant classification was published in 1998 by the Angiosperm Phylogeny Group. ... A modern system of plant taxonomy, the APG II system of plant classification was published in 2003 by the Angiosperm Phylogeny Group, APG, in Angiosperm Phylogeny Group (2003). ...

References and external links

1. ^ Mark W. Chase (2004). "Monocot relationships: an overview". American Journal of Botany 91: 1645-1655. 

• Chase MW, Soltis DE, Soltis PS, Rudall PJ, Fay MF, Hahn WJ, Sullivan S, Joseph J, Molvray M, Kores PJ, Givnish TJ, Sytsma KJ, Pires JC (2000). Higher-level systematics of the monocotyledons: An assessment of current knowledge and a new classification. In: Wilson KL, Morrison DA, eds. Monocots: Systematics and Evolution.. CSIRO, Melbourne. 3-16. ISBN 0-643-06437-0
• Tree of Life Web Project: Monocotyledons
• Numbers of threatened species by major groups of organisms (1996–2004). International Union for Conservation of Nature and Natural Resources. Retrieved on 2006 December 15.