Monocotyledons ( / ˌ m ɒ n ə ˌ k ɒ t ə ˈ l iː d ə n z / ), commonly referred to as monocots , ( Lilianae sensu Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon . They constitute one of the major groups into which the flowering plants have traditionally been divided; the rest of the flowering plants have two cotyledons and were classified as dicotyledons , or dicots.
78-627: See text Amaryllidoideae ( Amaryllidaceae s.s. , amaryllids ) is a subfamily of monocot flowering plants in the family Amaryllidaceae , order Asparagales . The most recent APG classification, APG III , takes a broad view of the Amaryllidaceae, which then has three subfamilies, one of which is Amaryllidoideae (the old family Amaryllidaceae), and the others are Allioideae (the old family Alliaceae) and Agapanthoideae (the old family Agapanthaceae). The subfamily consists of about seventy genera , with over eight hundred species , and
156-634: A division of Monocotyledons , using a modified form of Linnaeus' sexual classification but with the respective topography of stamens to carpels rather than just their numbers. The family Amaryllidaceae was named in 1805, by Jean Henri Jaume Saint-Hilaire . In 1810 Brown proposed that a subgroup of Liliaceae be distinguished on the basis of the position of the ovaries (inferior) and be referred to as Amaryllideae and in 1813 de Candolle described Liliacées Juss. and Amaryllidées Brown as two quite separate families. Samuel Frederick Gray 's A natural arrangement of British plants (1821). grouped together
234-444: A phylogenetic tree to be constructed for the flowering plants. The establishment of major new clades necessitated a departure from the older but widely used classifications such as Cronquist and Thorne, based largely on morphology rather than genetic data. These developments complicated discussions on plant evolution and necessitated a major taxonomic restructuring. This DNA based molecular phylogenetic research confirmed on
312-473: A brief history of the family) largely followed Hutchinson, but with four subfamilies ( Allioideae , Hemerocalloideae , Ixiolirioideae and Amaryllidoideae), the Amaryllidoideae he then divided further into two "infrafamilies", Amarylloidinae and Pancratioidinae , an arrangement with 23 tribes in total. In Dahlgren's system , a " splitter " who favoured larger numbers of smaller families, he adopted
390-719: A classification of flowering plants (florifera) based on a division by the number of cotyledons, but developed his ideas over successive publications, coining the terms Monocotyledones and Dicotyledones in 1703, in the revised version of his Methodus ( Methodus plantarum emendata ), as a primary method for dividing them, Herbae floriferae, dividi possunt, ut diximus, in Monocotyledones & Dicotyledones (Flowering plants, can be divided, as we have said, into Monocotyledons & Dicotyledons). Although Linnaeus (1707–1778) did not utilise Ray's discovery, basing his own classification solely on floral reproductive morphology ,
468-423: A complex picture that only partially related to the tribal structure considered up to that date, which had been based on morphology alone. Rather Amaryllidaceae resolved along biogeographical lines. A predominantly South African clade identified as Amaryllideae was a sister group to the rest of the family. The two other African tribes were Haemantheae and Cyrtantheae , and an Australasian tribe Calostemmateae
546-855: A diagnostic point of view the number of cotyledons is neither a particularly useful characteristic (as they are only present for a very short period in a plant's life), nor is it completely reliable. The single cotyledon is only one of a number of modifications of the body plan of the ancestral monocotyledons, whose adaptive advantages are poorly understood, but may have been related to adaption to aquatic habitats , prior to radiation to terrestrial habitats. Nevertheless, monocots are sufficiently distinctive that there has rarely been disagreement as to membership of this group, despite considerable diversity in terms of external morphology. However, morphological features that reliably characterise major clades are rare. Thus monocots are distinguishable from other angiosperms both in terms of their uniformity and diversity. On
624-474: A group, but with various taxonomic ranks and under several different names. The APG III system of 2009 recognises a clade called "monocots" but does not assign it to a taxonomic rank. The monocotyledons include about 70,000 species, about a quarter of all angiosperms. The largest family in this group (and in the flowering plants as a whole) by number of species are the orchids (family Orchidaceae ), with more than 20,000 species. About 12,000 species belong to
702-470: A leafless state, the narrow, shining-green, strap-like leaves usually preceding flowering and reaching a length of 25–30 cm. Flower colour is a purplish red or yellow with a tube sometimes paler and the anthers yellow. The list of Calostemma species, with their complete scientific name and authority, is given below. Due to their large and showy flowers, members of this genus are used as ornamental plants . This Amaryllidaceae article
780-573: A mixture of characteristics. Nymphaeaceae (water lilies) have reticulate veins, a single cotyledon, adventitious roots, and a monocot-like vascular bundle. These examples reflect their shared ancestry. Nevertheless, this list of traits is generally valid, especially when contrasting monocots with eudicots , rather than non-monocot flowering plants in general. Monocot apomorphies (characteristics derived during radiation rather than inherited from an ancestral form) include herbaceous habit, leaves with parallel venation and sheathed base, an embryo with
858-587: A narrower circumscription than Traub, using only the latter's Amaryllidoideae which he treated as nine tribes. Müller-Doblies described ten tribes (and 19 subtribes). Hickey and King described ten tribes by which the family were divided, such as the Zephyrantheae . Meerow and Snijder considered thirteen tribes, one ( Amaryllideae ) with two subtribes (For a comparison of these schemes see Meerow et al. 1999, Table I). Thus Traub's Amaryllidoideae, which most later authors treated as Amaryllidaceae s.s. , became
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#1732775589796936-487: A number of families having in common six equal stamens, a single style and a perianth that was simple and petaloid, within which he separated families by the characteristics of their fruit and seed, such as Amaryllideae, Liliaceae, Asphodeleae and Asparageae. John Lindley , in his An Introduction to the Natural System of Botany (1830) divided the "Monocotyledonous Plants" into two tribes. He then further divided
1014-662: A number of plants over the course of history. When Linnaeus formerly described the type genus Amaryllis , from which the family derives its name, in his Species Plantarum in 1753, there were nine species with this name. He placed Amaryllis in a grouping he referred to as Hexandria monogynia (i.e. six stamens and one pistil ) containing 51 genera in all in his sexual classification scheme. These genera have been treated as either liliaceous or amaryllidaceaeous (see Taxonomy of Liliaceae ) over time. In 1763 Michel Adanson placed them in ' Liliaceae ' In 1789 Antoine Laurent de Jussieu placed Amaryllis and related genera within
1092-483: A proximal leaf base or hypophyll and a distal hyperphyll. In monocots the hypophyll tends to be the dominant part in contrast to other angiosperms. From these, considerable diversity arises. Mature monocot leaves are generally narrow and linear, forming a sheathing around the stem at its base, although there are many exceptions. Leaf venation is of the striate type, mainly arcuate-striate or longitudinally striate (parallel), less often palmate-striate or pinnate-striate with
1170-582: A short axial body bearing leaves whose bases store food. Additional outer non-storage leaves may form a protective function (Tillich, Figure 12). Other storage organs may be tubers or corms , swollen axes. Tubers may form at the end of underground runners and persist. Corms are short lived vertical shoots with terminal inflorescences and shrivel once flowering has occurred. However, intermediate forms may occur such as in Crocosmia (Asparagales). Some monocots may also produce shoots that grow directly down into
1248-617: A similar position as a major division of the flowering plants throughout the nineteenth century, with minor variations. George Bentham and Hooker (1862–1883) used Monocotyledones, as would Wettstein , while August Eichler used Mononocotyleae and Engler , following de Candolle, Monocotyledoneae. In the twentieth century, some authors used alternative names such as Bessey 's (1915) Alternifoliae and Cronquist 's (1966) Liliatae. Later (1981) Cronquist changed Liliatae to Liliopsida, usages also adopted by Takhtajan simultaneously. Thorne (1992) and Dahlgren (1985) also used Liliidae as
1326-425: A single cotyledon, an atactostele , numerous adventitious roots, sympodial growth, and trimerous (3 parts per whorl ) flowers that are pentacyclic (5 whorled) with 3 sepals, 3 petals, 2 whorls of 3 stamens each, and 3 carpels. In contrast, monosulcate pollen is considered an ancestral trait, probably plesiomorphic . The distinctive features of the monocots have contributed to the relative taxonomic stability of
1404-586: A small 'core' represented by the tribe Tulipeae , while large groups such as Scilleae and Asparagae would become part of Asparagales either as part of the Amaryllidaceae or as separate families. Of the four tribes of the Amaryllidaceae, the Amaryllideae and Narcisseae would remain as core amaryllids while the Agaveae would be part of Asparagaceae but the Alstroemeriae would become a family within
1482-401: A smaller group were grass-like plants with long straight parallel veins. In doing so he distinguished between the dicotyledons, and the latter (grass-like) monocotyledon group, although he had no formal names for the two groups. Formal description dates from John Ray 's studies of seed structure in the 17th century. Ray, who is often considered the first botanical systematist , observed
1560-686: A synonym. Taxonomists had considerable latitude in naming this group, as the Monocotyledons were a group above the rank of family. Article 16 of the ICBN allows either a descriptive botanical name or a name formed from the name of an included family. In summary they have been variously named, as follows: Over the 1980s, a more general review of the classification of angiosperms was undertaken. The 1990s saw considerable progress in plant phylogenetics and cladistic theory, initially based on rbcL gene sequencing and cladistic analysis, enabling
1638-509: A typical inverted conical shape of the basal primary axis ( see Tillich, Figure 1). The limited conductivity also contributes to limited branching of the stems. Despite these limitations a wide variety of adaptive growth forms has resulted (Tillich, Figure 2) from epiphytic orchids (Asparagales) and bromeliads (Poales) to submarine Alismatales (including the reduced Lemnoideae ) and mycotrophic Burmanniaceae (Dioscreales) and Triuridaceae (Pandanales). Other forms of adaptation include
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#17327755897961716-523: A wide variety of infrafamilial classification systems have been proposed for the Amaryllidaceae s.s. . In the latter twentieth century there were at least six schemes, including Hutchinson (1926), Traub (1963), Dahlgren (1985), Müller-Doblies and Müller-Doblies (1996), Hickey and King (1997) and Meerow and Snijman (1998). Hutchinson was an early proponent of the larger Amaryllidaceae, transferring taxa from Liliaceae and had three tribes, Agapantheae , Allieae and Gilliesieae . Traub (who provides
1794-573: A worldwide distribution. The Amaryllidoideae are herbaceous , perennial flowering plants , usually with bulbs (some are rhizomatous ). Their fleshy leaves are arranged in two vertical columns, and their flowers are large. Most of them are bulbous geophytes and many have a long history of cultivation as ornamental plants . They are distinguished from the other two Amaryllidaceae subfamilies ( Agapanthoideae and Allioideae ) by their unique alkaloidal chemistry, inferior ovary , and hollow style . The name Amaryllis had been applied to
1872-466: 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 . A number of these differences are not unique to the monocots, and, while still useful, no one single feature will infallibly identify a plant as a monocot. For example, trimerous flowers and monosulcate pollen are also found in magnoliids , and exclusively adventitious roots are found in some of
1950-423: Is petiolate. The consequent petiolate Eucharideae/Stenomesseae subclade could not be further resolved into distinct monophyletic tribes. Subsequent treatment has been variable. Meerow et al. state here that this subclade should be called Stenomesseae because the type species of Stenomesson was petiolate and thus transferred from the former Stenomesseae into the new petiolate clade. Subsequently, Meerow (2004) treated
2028-521: Is recognised as a distinct tribe within the Hippeastroid clade, and Stenomesseae is recognised as polyphyletic with two distinct types based on leaf shape and subsequent creation of Clinanthieae as a separate grouping (see Cladogram ), the remainder being submerged into Eucharideae. Additional tribes: The subfamily includes about 70 genera arranged in tribes and subtribes. Monocot Monocotyledons have almost always been recognized as
2106-499: Is the name that has been most commonly used since the publication of the Angiosperm Phylogeny Group (APG) system in 1998 and regularly updated since. Within the angiosperms, there are two major grades , a small early branching basal grade, the basal angiosperms (ANA grade) with three lineages and a larger late branching grade, the core angiosperms (mesangiosperms) with five lineages, as shown in
2184-759: Is their growth pattern, lacking a lateral meristem ( cambium ) that allows for continual growth in diameter with height ( secondary growth ), and therefore this characteristic is a basic limitation in shoot construction. Although largely herbaceous, some arboraceous monocots reach great height, length and mass. The latter include agaves , palms , pandans , and bamboos . This creates challenges in water transport that monocots deal with in various ways. Some, such as species of Yucca , develop anomalous secondary growth, while palm trees utilise an anomalous primary growth form described as establishment growth ( see Vascular system ). The axis undergoes primary thickening, that progresses from internode to internode, resulting in
2262-683: Is usually fugacious (short lived). Some of the more persistent perigones demonstrate thermonastic opening and closing (responsive to changes in temperature). About two thirds of monocots are zoophilous , predominantly by insects . These plants need to advertise to pollinators and do so by way of phaneranthous (showy) flowers. Such optical signalling is usually a function of the tepal whorls but may also be provided by semaphylls (other structures such as filaments , staminodes or stylodia which have become modified to attract pollinators). However, some monocot plants may have aphananthous (inconspicuous) flowers and still be pollinated by animals. In these
2340-721: Is whose pulp is divided into two lobes and a radicle... 2. Such which neither spring out of the ground with seed leaves nor have their pulp divided into lobes John Ray (1674), pp. 164, 166 Since this paper appeared a year before the publication of Malpighi 's Anatome Plantarum (1675–1679), Ray has the priority. At the time, Ray did not fully realise the importance of his discovery but progressively developed this over successive publications. And since these were in Latin, "seed leaves" became folia seminalia and then cotyledon , following Malpighi . Malpighi and Ray were familiar with each other's work, and Malpighi in describing
2418-614: The Liliales . Since then seven of Linnaeus' genera have consistently been placed in a common taxonomic unit of amaryllids, based on the inferior position of the ovaries (whether this be as an order, suborder, family, subfamily, tribe or section). Thus much of what we now consider Amaryllidoideae remained in Liliaceae because the ovary was superior, till 1926 when John Hutchinson transferred them to Amaryllidaceae. The number of known genera within these families continued to grow, and by
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2496-470: The Petaloidea ( petaloid monocots ), into 32 orders, including the Amaryllideae. He defined the latter as "Hexapetaloideous bulbous hexandrous monocotyledons, with an inferior ovarium, a 6-parted perianthium with equitant sepals, and flat spongy seeds" and included Amaryllis , Phycella , Nerine , Vallota , and Calostemma . By 1846 Lindley had greatly expanded and refined the treatment of
2574-593: The Piperaceae . Similarly, at least one of these traits, parallel leaf veins, is far from universal among the monocots. Broad leaves and reticulate leaf veins, features typical of dicots, are found in a wide variety of monocot families: for example, Trillium , Smilax (greenbriar), Pogonia (an orchid), and the Dioscoreales (yams). Potamogeton and Paris quadrifolia (herb-paris) are examples of monocots with tetramerous flowers. Other plants exhibit
2652-441: The alliaceous ( i.e. Allioideae ) elements. Hutchinson also suggested that the elements now included in Amaryllidoideae's parent family (Amaryllidaceae) could all be placed in one family, although only Cronquist placed all the elements into a very large Liliaceae. The introduction of molecular methods in the 1990s confirmed the affinity of three major taxa corresponding to Alliaceae , Agapanthaceae and Amaryllidaceae. In 2009
2730-450: The cladogram . Amborellales Nymphaeales Austrobaileyales magnoliids Chloranthales monocots Ceratophyllales eudicots While the monocotyledons have remained extremely stable in their outer borders as a well-defined and coherent monophylectic group, the deeper internal relationships have undergone considerable flux, with many competing classification systems over time. Historically, Bentham (1877), considered
2808-537: The dichotomy of cotyledon structure in his examination of seeds. He reported his findings in a paper read to the Royal Society on 17 December 1674, entitled "A Discourse on the Seeds of Plants". The greatest number of plants that come of seed spring at first out of the earth with two leaves which being for the most part of a different figure from the succeeding leaves are by our gardeners not improperly called
2886-440: The eudicots are the largest and most diversified angiosperm radiations , accounting for 22.8% and 74.2% of all angiosperm species respectively. Of these, the grass family (Poaceae) is the most economically important, which together with the orchids Orchidaceae account for half of the species diversity, accounting for 34% and 17% of all monocots respectively, and are among the largest families of angiosperms. They are also among
2964-530: The lilioid monocots ; major cereal grains ( maize , rice , barley , rye , oats , millet , sorghum and wheat ) in the grass family ; and forage grasses ( Poales ) as well as woody tree-like palm trees ( Arecales ), bamboo , reeds and bromeliads (Poales), bananas and ginger ( Zingiberales ) in the commelinid monocots , as well as both emergent (Poales, Acorales ) and aroids , as well as floating or submerged aquatic plants such as seagrass ( Alismatales ). The most important distinction
3042-418: The phyletic system that superseded it in the late nineteenth century, based on an understanding of the acquisition of characteristics. He also made the crucial observation Ex hac seminum divisione sumum potest generalis plantarum distinctio, eaque meo judicio omnium prima et longe optima, in eas sci. quae plantula seminali sunt bifolia aut διλόβω, et quae plantula sem. adulta analoga. (From this division of
3120-471: The suffix -florae was replaced with -anae ( e.g. Alismatanae ) and the number of superorders expanded to ten with the addition of Bromelianae, Cyclanthanae and Pandananae. Molecular studies have both confirmed the monophyly of the monocots and helped elucidate relationships within this group. The APG system does not assign the monocots to a taxonomic rank, instead recognizing a monocots clade. However, there has remained some uncertainty regarding
3198-625: The American clade suggested the presence of two groups, the Andean clade and a further "Hippeastroid" clade, in which Griffineae was sister to the rest of the clade (Hippeastreae). Similarly within the Andean clade four subclades were identified, including Eustephieae which appeared as sister to the remaining clade, including Hymenocallideae . Of the remaining taxa, two subclades emerged that did not correspond to existing tribal structure, namely Eucharideae (3 genera) and Stenomesseae (6 genera). Rather
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3276-536: The Andean clade as having four tribes with Eucharis in Stenomesseae. However, since then the term Eucharideae has been used instead. For example, in a paper presented at Monocot IV (2008), a cladogram published in 2013, and in 2014 only Eucharideae is mentioned while in 2015 Meerow described new species of Stenomesson and Eucharis as being in Eucharideae. The combined clade would include Stenomessaea as
3354-643: The Angiosperm Phylogeny Group (APG) decided to amalgamate the three families, which together form a monophyletic group, into a single family, at first called Alliaceae and then Amaryllidaceae. The three families then became reduced to subfamilies, so that the historical Amaryllidaceae became subfamily Amaryllidoideae. To distinguish this new broader family from the older narrower family it has become customary to refer to Amaryllidaceae sensu APG, or as used by APG, Amaryllidaceae s.l. . as opposed to Amaryllidaceae s.s. . The relationships between
3432-733: The ability to increase the width of a stem ( secondary growth ) via the same kind of vascular cambium found in non-monocot woody plants . However, some monocots do have secondary growth; because this does not arise from a single vascular cambium producing xylem inwards and phloem outwards, it is termed "anomalous secondary growth". Examples of large monocots which either exhibit secondary growth, or can reach large sizes without it, are palms ( Arecaceae ), screwpines ( Pandanaceae ), bananas ( Musaceae ), Yucca , Aloe , Dracaena , and Cordyline . The monocots form one of five major lineages of mesangiosperms (core angiosperms), which in themselves form 99.95% of all angiosperms . The monocots and
3510-462: The angiosperms. Correlation with morphological criteria showed that the defining feature was not cotyledon number but the separation of angiosperms into two major pollen types, uniaperturate ( monosulcate and monosulcate-derived) and triaperturate (tricolpate and tricolpate-derived), with the monocots situated within the uniaperturate groups. The formal taxonomic ranking of Monoctyledons thus became replaced with monocots as an informal clade. This
3588-455: The basis for Amaryllidoideae sensu APGIII . Of the other three subfamilies in Traub's system, Allioideae represents Amaryllidaceae subfamily Allioideae sensu APGIII. Hemerocalloideae was a small subfamily with a single tribe, Hemerocalleae consisting of two genera, Hemerocallis and Leucocrinum . Subsequent research has shown these to be very different taxa, Hemerocallis being placed in
3666-624: The clade of interest) divergence times in mya (million years ago). Acorales Alismatales Petrosaviales Dioscoreales (115 MYA) Pandanales (91 MYA) Calostemma See text Calostemma is a small genus of herbaceous , perennial and bulbous plants in the Amaryllis family ( Amaryllidaceae , subfamily Amaryllidoideae ), commonly known as Wilcannia Lily . It consists of three species endemic to Australia , where they are distributed in arid regions with summer precipitation. Members of Calostemma often flower in
3744-421: The climbing vines of Araceae (Alismatales) which use negative phototropism ( skototropism ) to locate host trees ( i.e. the darkest area), while some palms such as Calamus manan ( Arecales ) produce the longest shoots in the plant kingdom, up to 185 m long. Other monocots, particularly Poales , have adopted a therophyte life form . The cotyledon, the primordial Angiosperm leaf consists of
3822-484: The cotyledons were critical to the development of the plant, proof that Ray required for his theory. In his Methodus plantarum nova Ray also developed and justified the "natural" or pre-evolutionary approach to classification, based on characteristics selected a posteriori in order to group together taxa that have the greatest number of shared characteristics. This approach, also referred to as polythetic would last till evolutionary theory enabled Eichler to develop
3900-404: The dominant members of many plant communities. The monocots are one of the major divisions of the flowering plants or angiosperms. They have been recognized as a natural group since the sixteenth century when Lobelius (1571), searching for a characteristic to group plants by, decided on leaf form and their venation . He observed that the majority had broad leaves with net-like venation, but
3978-419: The exact relationships between the major lineages, with a number of competing models (including APG). The APG system establishes eleven orders of monocots. These form three grades, the alismatid monocots , lilioid monocots and the commelinid monocots by order of branching, from early to late. In the following cladogram numbers indicate crown group (most recent common ancestor of the sampled species of
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#17327755897964056-816: The family Xanthorrhoeaceae , while Leucocrinum belongs in Asparagaceae, both part of Asparagales . Finally Ixiolirioideae was another very small subfamily, with two tribes, Gageeae and Ixiolirieae. Gageeae consisted of two genera, Gagea and Giraldiella , which was subsequently merged with Gagea ( Liliaceae , Liliales), while Ixiolirieae similarly contained only Ixiolirion and Kolpakowskia (merged with Ixiolirion ) belongs in Ixioliriaceae (Asparagales). so only two of his subfamilies now belong in Amaryllidaceae s.l. . Traubiinae Stenomesseae/Eucharideae Griffineae Hymenocallideae Calostemmateae The further application of molecular phylogenetics produced
4134-423: The group. Douglas E. Soltis and others identify thirteen synapomorphies (shared characteristics that unite monophyletic groups of taxa); Monocots have a distinctive arrangement of vascular tissue known as an atactostele in which the vascular tissue is scattered rather than arranged in concentric rings. Collenchyma is absent in monocot stems, roots and leaves. Many monocots are herbaceous and do not have
4212-464: The leaf veins emerging at the leaf base and then running together at the apices. There is usually only one leaf per node because the leaf base encompasses more than half the circumference. The evolution of this monocot characteristic has been attributed to developmental differences in early zonal differentiation rather than meristem activity (leaf base theory). The lack of cambium in the primary root limits its ability to grow sufficiently to maintain
4290-419: The monocots to consist of four alliances , Epigynae, Coronariae, Nudiflorae and Glumales, based on floral characteristics. He describes the attempts to subdivide the group since the days of Lindley as largely unsuccessful. Like most subsequent classification systems it failed to distinguish between two major orders, Liliales and Asparagales , now recognised as quite separate. A major advance in this respect
4368-573: The monocots. He placed the Liliaceae within the Liliales , but saw it as a paraphyletic ("catch-all") family, being all Liliales not included in the other orders, hoping that the future would reveal some characteristic that would group them better. This kept the Liliaceae. separate from the Amaryllidaceae, which was divided into four tribes (with 68 genera), yet both his Amaryllidaceae and Liliaceae contained many genera that would eventually segregate to each other's contemporary orders (Liliales and Asparagales respectively). The Liliaceae would be reduced to
4446-411: The name implies, a single (mono-) cotyledon , or embryonic leaf, in their seeds . Historically, this feature was used to contrast the monocots with the dicotyledons or dicots which typically have two cotyledons; however, modern research has shown that the dicots are not a natural group, and the term can only be used to indicate all angiosperms that are not monocots and is used in that respect here. From
4524-400: The one hand that the monocots remained as a well defined monophyletic group or clade , in contrast to the other historical divisions of the flowering plants, which had to be substantially reorganized. No longer could the angiosperms be simply divided into monocotyledons and dicotyledons; it was apparent that the monocotyledons were but one of a relatively large number of defined groups within
4602-520: The one hand, the organization of the shoots, leaf structure, and floral configuration are more uniform than in the remaining angiosperms, yet within these constraints a wealth of diversity exists, indicating a high degree of evolutionary success. Monocot diversity includes perennial geophytes such as ornamental flowers including orchids ( Asparagales ); tulips and lilies ( Liliales ); rosette and succulent epiphytes (Asparagales); mycoheterotrophs (Liliales, Dioscoreales , Pandanales ), all in
4680-511: The plant. This necessitates early development of roots derived from the shoot (adventitious roots). In addition to roots, monocots develop runners and rhizomes , which are creeping shoots. Runners serve vegetative propagation , have elongated internodes , run on or just below the surface of the soil and in most case bear scale leaves . Rhizomes frequently have an additional storage function and rhizome producing plants are considered geophytes (Tillich, Figure 11). Other geophytes develop bulbs ,
4758-535: The plants rely either on chemical attraction or other structures such as coloured bracts fulfill the role of optical attraction. In some phaneranthous plants such structures may reinforce floral structures. The production of fragrances for olfactory signalling are common in monocots. The perigone also functions as a landing platform for pollinating insects. The embryo consists of a single cotyledon, usually with two vascular bundles . The traditionally listed differences between monocots and dicots are as follows. This
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#17327755897964836-429: The reduced Stenomesson ( sensu stricto ), Rauhia , Phaedranassa , and Eucrosia , together with Eucharideae as Eucharis , Caliphruria , and Urceolina . Based on the oldest published name for the remaining lorate Stenomesson species, which is Clinanthus , the lorate subclade was designated tribe Clinantheae , and the remaining species transferred. In this redescription, Clinanthus luteus becomes
4914-439: The remaining Mediterranean tribes. These relationships are summarised in the following cladogram: Tribe Amaryllideae Tribe Cyrtantheae Tribe Haemantheae Tribe Calostemmateae Tribe Lycorideae Tribe Galantheae Tribe Pancratieae Tribe Narcisseae Tribe Griffineae Tribe Hippeastreae Tribe Eustephieae Eucharideae / Stenomesseae Tribe Clinantheae Tribe Hymenocallideae Publication of
4992-482: The same structures had introduced the term cotyledon, which Ray adopted in his subsequent writing. Mense quoque Maii, alias seminales plantulas Fabarum, & Phaseolorum, ablatis pariter binis seminalibus foliis, seu cotyledonibus, incubandas posui In the month of May, also, I incubated two seed plants, Faba and Phaseolus , after removing the two seed leaves, or cotyledons Marcello Malpighi (1679), p. 18 In this experiment, Malpighi also showed that
5070-425: The seed leaves... In the first kind the seed leaves are nothing but the two lobes of the seed having their plain sides clapt together like the two halves of a walnut and therefore are of the just figure of the seed slit in sunder flat wise... Of seeds that spring out of the earth with leaves like the succeeding and no seed leaves I have observed two sorts. 1. Such as are congenerous to the first kind precedent that
5148-400: The seeds derives a general distinction amongst plants, that in my judgement is first and by far the best, into those seed plants which are bifoliate, or bilobed, and those that are analogous to the adult), that is between monocots and dicots. He illustrated this by quoting from Malpighi and including reproductions of Malpighi's drawings of cotyledons (see figure). Initially Ray did not develop
5226-445: The soil, these are geophilous shoots (Tillich, Figure 11) that help overcome the limited trunk stability of large woody monocots. In nearly all cases the perigone consists of two alternating trimerous whorls of tepals , being homochlamydeous , without differentiation between calyx and corolla . In zoophilous (pollinated by animals) taxa, both whorls are corolline (petal-like). Anthesis (the period of flower opening)
5304-403: The specific issue regarding Liliales and Asparagales, Dahlgren followed Huber (1969) in adopting a splitter approach, in contrast to the longstanding tendency to view Liliaceae as a very broad sensu lato family . Following Dahlgren's untimely death in 1987, his work was continued by his widow, Gertrud Dahlgren , who published a revised version of the classification in 1989. In this scheme
5382-485: The subfamilies within the Amaryllidaceae and the place of Amaryllidoideae is shown in the Cladogram . Subfamily Agapanthoideae Subfamily Allioideae Subfamily Amaryllidoideae Complete resolution of infrafamilial (suprageneric) relationships within subfamily Amaryllidoideae (Amaryllidaceae s.s. ) has proven difficult. Early studies lacked sufficient resolution for further elucidation of this group. Historically
5460-407: The taxa segregated on a morphological criterion, namely leaf shape. Stenomesseae was recognised as polyphyletic with two distinct types based on leaf shape ( lorate -leafed and petiolate -leafed), while Eucharideae was petiolate, together with three Stenomesseae genera and a number of species of the type genus Stenomesson . Furthermore, the type species of Stenomesson , Stenomesson flavum
5538-490: The term was used shortly after his classification appeared (1753) by Scopoli and who is credited for its introduction. Every taxonomist since then, starting with De Jussieu and De Candolle , has used Ray's distinction as a major classification characteristic. In De Jussieu's system (1789), he followed Ray, arranging his Monocotyledones into three classes based on stamen position and placing them between Acotyledones and Dicotyledones. De Candolle's system (1813) which
5616-551: The third version of the APG classification and acceptance of Amaryllidaceae s.l. was accompanied by a listing of accepted subfamily and tribal names, since the change in rank from family to subfamily necessitated a revision of other lower ranks, as follows: Family: Amaryllidaceae J.St.-Hil. , Expos. Fam. Nat. 1: 134. Feb–Apr 1805, nom. cons. This circumscription differs from the phylogenetic descriptions of Meerow and colleagues in several respects, as described above. Griffineae
5694-559: The time of the Bentham and Hooker classification (1883) the Amaryllidaceae (Amaryllideae) were divided into four tribes, of which only one (Amarylleae) still represents the grouping now reflected in Amarylloideae. In the post-Darwinian era the amaryllids were mainly treated as part of a very large family Liliaceae, although the early twentieth century saw increasing doubts about the inclusion of many of its components, particularly
5772-458: The true grasses ( Poaceae ), which are economically the most important family of monocotyledons. Often mistaken for grasses, sedges are also monocots. In agriculture the majority of the biomass produced comes from monocotyledons. These include not only major grains ( rice , wheat , maize , etc.), but also forage grasses, sugar cane , the bamboos , and many other common food and decorative crops. The monocots or monocotyledons have, as
5850-478: The type species for tribe Clinantheae which includes Pamianthe , Paramongaia and Pucara . Although subsequent analysis resulted in submerging Pucara into Stenomesson (and hence Stenomesseae), rather than treating it as a separate genus. The Eurasian clade was also further resolved (for historical treatment, see Table I Meerow et al. 2006) into four tribes, Pancratieae , Narcisseae , Galantheae and Lycorideae . This positioned Lycorideae as sister to
5928-455: Was also identified, but a large clade could only be described as Eurasian and American, each of which were monophyletic sister clades to each other. The Eurasian clade was poorly resolved with the exception of Lycorideae (Central and East Asian). The American clade was better resolved identifying both Hippeastreae as a tribe (and Zephyranthinae as a subtribe within it). The American clade also included an Andean clade Further investigation of
6006-559: Was the work of Rolf Dahlgren (1980), which would form the basis of the Angiosperm Phylogeny Group 's (APG) subsequent modern classification of monocot families. Dahlgren who used the alternate name Lilliidae considered the monocots as a subclass of angiosperms characterised by a single cotyledon and the presence of triangular protein bodies in the sieve tube plastids . He divided the monocots into seven superorders , Alismatiflorae, Ariflorae, Triuridiflorae, Liliiflorae , Zingiberiflorae, Commeliniflorae and Areciflorae. With respect to
6084-468: Was to predominate thinking through much of the 19th century used a similar general arrangement, with two subgroups of his Monocotylédonés (Monocotyledoneae). Lindley (1830) followed De Candolle in using the terms Monocotyledon and Endogenae interchangeably. They considered the monocotyledons to be a group of vascular plants ( Vasculares ) whose vascular bundles were thought to arise from within ( Endogènes or endogenous ). Monocotyledons remained in
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