Cotyledon - wikipedia Cotyledon For other uses, see Cotyledon ( disambiguation ). Not to be confused with Cotyledion. Not to be confused with Cotylenol. Cotyledon from a Judas - tree ( Cercis siliquastrum ) seedling Comparison of a monocot and dicot sprouting. The visible part of the monocot plant ( left ) is actually the first true leaf produced from the meristem ; the cotyledon itself remains within the seed Schematic of epigeal vs hypogeal germination Peanut seeds cut in half showing the embryos with cotyledons and primordial root. Two - weeks - old cotyledons of Douglas - fir. A seedling of Pinus halepensis with eight cotyledons A cotyledon ( / kɒtɪˈliːdən / ; `` seed leaf '' from Latin cotyledon, from Greek : κοτυληδών kotylēdōn, gen. : κοτυληδόνος kotylēdonos, from κοτύλη kotýlē `` cup, bowl '' ) is a significant part of the embryo within the seed of a plant, and is defined by the Oxford English Dictionary as `` The primary leaf in the embryo of the higher plants ( Phanerogams ) ; the seed - leaf. '' Upon germination, the cotyledon may become the embryonic first leaves of a seedling. The number of cotyledons present is one characteristic used by botanists to classify the flowering plants ( angiosperms ). Species with one cotyledon are called monocotyledonous ( `` monocots '' ). Plants with two embryonic leaves are termed dicotyledonous ( `` dicots '' ) and placed in the class Magnoliopsida. In the case of dicot seedlings whose cotyledons are photosynthetic, the cotyledons are functionally similar to leaves. However, true leaves and cotyledons are developmentally distinct. Cotyledons are formed during embryogenesis, along with the root and shoot meristems, and are therefore present in the seed prior to germination. True leaves, however, are formed post-embryonically ( i.e. after germination ) from the shoot apical meristem, which is responsible for generating subsequent aerial portions of the plant. The cotyledon of grasses and many other monocotyledons is a highly modified leaf composed of a scutellum and a coleoptile. The scutellum is a tissue within the seed that is specialized to absorb stored food from the adjacent endosperm. The coleoptile is a protective cap that covers the plumule ( precursor to the stem and leaves of the plant ). Gymnosperm seedlings also have cotyledons, and these are often variable in number ( multicotyledonous ), with from 2 to 24 cotyledons forming a whorl at the top of the hypocotyl ( the embryonic stem ) surrounding the plumule. Within each species, there is often still some variation in cotyledon numbers, e.g. Monterey pine ( Pinus radiata ) seedlings have 5 -- 9, and Jeffrey pine ( Pinus jeffreyi ) 7 -- 13 ( Mirov 1967 ), but other species are more fixed, with e.g. Mediterranean cypress always having just two cotyledons. The highest number reported is for big - cone pinyon ( Pinus maximartinezii ), with 24 ( Farjon & Styles 1997 ). The cotyledons may be ephemeral, lasting only days after emergence, or persistent, enduring at least a year on the plant. The cotyledons contain ( or in the case of gymnosperms and monocotyledons, have access to ) the stored food reserves of the seed. As these reserves are used up, the cotyledons may turn green and begin photosynthesis, or may wither as the first true leaves take over food production for the seedling. Contents 1 Epigeal versus hypogeal development 2 History 3 Notes 4 References 5 Bibliography 6 External links Epigeal versus hypogeal development Main articles : Epigeal germination and Hypogeal germination Cotyledons may be either epigeal, expanding on the germination of the seed, throwing off the seed shell, rising above the ground, and perhaps becoming photosynthetic ; or hypogeal, not expanding, remaining below ground and not becoming photosynthetic. The latter is typically the case where the cotyledons act as a storage organ, as in many nuts and acorns. Hypogeal plants have ( on average ) significantly larger seeds than epigeal ones. They are also capable of surviving if the seedling is clipped off, as meristem buds remain underground ( with epigeal plants, the meristem is clipped off if the seedling is grazed ). The tradeoff is whether the plant should produce a large number of small seeds, or a smaller number of seeds which are more likely to survive. Related plants show a mixture of hypogeal and epigeal development, even within the same plant family. Groups which contain both hypogeal and epigeal species include, for example, the Araucariaceae family of Southern Hemisphere conifers, the Fabaceae ( pea family ), and the genus Lilium ( see Lily seed germination types ). The frequently garden grown common bean - Phaseolus vulgaris - is epigeal while the closely related runner bean - Phaseolus coccineus - is hypogeal. History The term cotyledon was coined by Marcello Malpighi ( 1628 -- 1694 ). John Ray was the first botanist to recognize that some plants have two and others only one, and eventually the first to recognize the immense importance of this fact to systematics, in Methodus plantarum ( 1682 ). Theophrastus ( 3rd or 4th century BC ) and Albertus Magnus ( 13th century ) may also have recognized the distinction between the dicotyledons and monocotyledons. Notes Jump up ^ The Oxford English Dictionary attributes it Linnaeus ( 1707 -- 1778 ) `` 1751 Linnaeus Philos. Bot. 54. Cotyledon, corpus laterale seminis, bibulum, caducum '' and 89, by analogy with a similar structure of the same name in the placenta. References Jump up ^ Short & George 2013, p. 15. ^ Jump up to : OED 2015. ^ Jump up to : Vines, Sydney Howard ( 1913 ), `` Robert Morison 1620 -- 1683 and John Ray 1627 -- 1705 '', in Oliver, Francis Wall, Makers of British botany, Cambridge University Press, pp. 8 -- 43 ^ Jump up to : Charles R. Tischler ; Justin D. Derner ; H. Wayne Polley ; Hyrum B. Johnson, Response of Seedlings of Two Hypogeal Brush Species to CO2 Enrichment, Fort Collins, CO : U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, pp. 104 -- 106 Jump up ^ Baraloto, C. ; Forget, P. - M. ( 2007 ), `` Seed size, seedling morphology, and response to deep shade and damage in neotropical rain forest trees '', American Journal of Botany, 94 ( 6 ) : 901 -- 11, PMID 21636459, doi : 10.3732 / ajb. 94.6. 901 Jump up ^ Hiroaki Setoguchi ; Takeshi Asakawa Osawa ; Jean - Christophe Pintaud ; Tanguy Jaffré ; Jean - Marie Veillon ( 1998 ), `` Phyloghuhenetic relationships within Araucariaceae based on rbcL gene sequences '', American Journal of Botany, 85 ( 11 ) : 1507 -- 1516, JSTOR 2446478, PMID 21680310, doi : 10.2307 / 2446478 Jump up ^ Linnaeus 1751, p. 54. Jump up ^ Linnaeus 1751, p. 89. Jump up ^ Greene, E.L. & Egerton, F.N. ( ed. ) ( 1983 ). Landmarks of Botanical History : Part 2. Stanford : Stanford University Press, p. 1019, note 15, ( 1 ). Jump up ^ http://bioetymology.blogspot.com.br/2011/06/cotyledon-monocotyledon-plural-usually.html Jump up ^ Greene, E.L. & Egerton, F.N. ( ed. ) ( 1983 ), p. 1019, note 15. Bibliography Linnaeus, Carl ( 1755 ) ( 1751 ). Philosophia botanica : in qua explicantur fundamenta botanica cum definitionibus partium, exemplis terminorum, observationibus rariorum, adiectis figuris aeneis. originally published simultaneously by R. Kiesewetter ( Stockholm ) and Z. Chatelain ( Amsterdam ). Vienna : Joannis Thomae Trattner. Retrieved 13 December 2015. Mirov, N.T. ( 1967 ). The Genus Pinus. Ronald Press Company, New York. Farjon, A. & Styles, B.T. ( 1997 ). Pinus ( Pinaceae ). Flora Neotropica Monograph 75 : 221 - 224. `` Cotyledon ''. Oxford English Dictionary ( 3rd ed. ). Oxford University Press. September 2005. ( Subscription or UK public library membership required. ) Short, Emma ; George, Alex ( 2013 ). A primer of botanical Latin with vocabulary. New York : Cambridge University Press. ISBN 9781107693753. Retrieved 14 December 2015. External links Tiscali. reference - Cotyledon Wikimedia Commons has media related to Cotyledon. Look up cotyledon in Wiktionary, the free dictionary. Retrieved from `` https://en.wikipedia.org/w/index.php?title=Cotyledon&oldid=796783414 '' Categories : Plant anatomy Plant morphology Plant reproduction Leaves Talk Contents About Wikipedia Azərbaycanca Bân - lâm - gú Беларуская Català Čeština Dansk Deutsch Eesti Ελληνικά Español Esperanto Euskara فارسی Français Gaeilge Galego हिन्दी Hrvatski Ido Bahasa Indonesia Íslenska Italiano Basa Jawa ქართული Magyar Bahasa Melayu Nederlands 日本 語 Polski Português Română Runa Simi Русский Scots Simple English Slovenčina Српски / srpski Srpskohrvatski / српскохрватски Suomi Svenska Türkçe Українська 中文 Edit links This page was last edited on 23 August 2017, at 01 : 34. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: an angiosperm with one embryonic leaf present in its seeds is called a(n)
Answer: monocotyledonous ("monocots")