Acta 111, pp 1 15. ref In most other embryophyte land plants , the gametophyte is very small. In fern s the gametophyte is a free living organism called the prothallus , in contrast to angiosperms ... council for Science and the Environment . Washington, DC ref In gymnosperm s and angiosperm s, the gametophyte are reduced to only a few cells in angiosperms the female gametophyte sometimes called the embryo sac is known as a megagametophyte and the male gametophyte pollen is called a microgametophyte ... and gametophytes are often isomorphic , but in some species the gametophyte may be reduced ... more details
A sporeling is a young plant or fungus produced by a germinated spore , similar to a seedling derived from a germinated seed . They occur in alga e, fungus fungi , lichen s, bryophyte s and Pteridophyte seedless vascular plant s. Sporeling development Most spores germinate by first producing a germ rhizoid or holdfast followed by a germ tube emerging from the opposite end. The germ tube develops into the hypha , protonema or thallus tissue thallus of the gametophyte . In seedless vascular plants such as fern s and lycopodiophyta , the term sporeling refers to the young sporophyte growing on the gametophyte. These sporelings develop via an embryo stage from a fertilized egg inside an archegonium and depend on the gametophyte for their early stages of growth before becoming independent sporophytes. Young fern sporelings can often be found with the prothallus gametophyte still attached at the base of their frond s. External links British Pteridological Society http www.nhm.ac.uk hosted sites bps wof wof.htm An introduction to ferns contains a picture of a sporeling fern attached to the prothallus botany stub Category Plant morphology Category Plant reproduction Category Fungal morphology and anatomy ... more details
gametophyte stage on which the adult sporophyte is dependent on the gametophyte for nutrition. The embryo ... early development is therefore nurtured by the gametophyte. ref Ralf Reski 1998 Development, genetics ... patens Most algae have dominant gametophyte generations, but in some species the gametophytes .... These endosporic megaspores contained within them a miniature multicellular female gametophyte complete ... the gametophyte phase. Proceedings of the National Academy of Sciences 102, 5892 5897. P.R. Bell ... more details
Image Physcomitrella Protonema.jpg thumb Protonema cells of the moss Physcomitrella patens A protonema plural protonemata is a thread like chain of cells that forms the earliest stage the haploid phase of a bryophyte life cycle. When a moss first grows from the spore , it grows as a protonema which develops into a leafy gametophore . Marchantiophyta Liverworts do not have a protonemal stage, the spores Germination germinate directly into a new Gametophyte generation. Moss spores Germination germinate to form an alga like filamentous structure called the protonema. It represents the juvenile gametophyte . While the protonema is growing by apical cell division, at some stage, under the influence of the phytohormone cytokinin , bud s are induced which grow by three faced apical cells. These give rise to gametophore s, stems and leaf like structures bryophytes do not have true leaves megaphyll . These gametophores are the adult form of the gametophyte ref Ralf Reski 1998 Developmental biology Development , genetics and molecular biology of moss es. Botanica Acta 111, 1 15. ref . Protonema are characteristic of all mosses and some liverworts but are absent from hornwort s. The protonema is also the photosynthetic part of a germinating fern spore. References reflist botany stub Category Bryophytes cs Prvokl ek de Protonema es Protonema fr Protonema pl Spl tek pt Protonema ru sv Protonema uk zh ... more details
being the gametophyte prothallium in season. This basic pattern is like that found in the seed plants but with an important exception. Unlike the seed plants, the pteridophytes have a gametophyte stage ... types of gametophyte sexuality Dioicous pteridophytes produce only antheridium antheridia male organs or archegonium archegonia female organ on a single gametophyte body. Monoicous pteridophytes produce both antheridium antheridia and archegonium archegonia on the same gametophyte body. Protandrous ... one or both kinds of gametophyte. Those terms apply only to Spermatophyte seed plants . See also commons ... more details
a haploid gametophyte, there is only one allele for any Genetics genetic trait. Thus, all alleles ... expression cannot be masked and will cause the gametophyte to die thus, the trait cannot be passed ... more details
italic title Taxobox name Weft fern image Trichomanes intricatum2 BobKlips.jpg caption Trichomanes intricatum regnum Plantae divisio Polypodiophyta classis Polypodiopsida ordo Hymenophyllales familia Hymenophyllaceae genus Trichomanes species T. intricatum binomial Trichomanes intricatum binomial authority Donald R. Farrar Farrar Image Trichomanes intricatum1 BobKlips.jpg left thumb Trichomanes intricatum Image Trichomanes intricatum3 BobKlips.jpg left thumb Closeup of T. intricatum Trichomanes intricatum is known as the weft fern . This is an unusual filmy fern that grows in rock shelters and crevices in the eastern United States , being known only from its gametophyte generation. It is a rare plant that is protected in several states. Recent study has found a relationship between this species and an Asian filmy fern species, Crepidomanes schmidtianum . Both share the same chloroplast genome . The relationship is uncertain. References Farrar, Donald R. Trichomanes intricatum The Independent Trichomanes Gametophyte in the Eastern United States. American Fern Journal , 82 2 68 74. 1992. Ebihara, Atsushi, Donald R. Farrar, and Motomi Ito. The sporophyte less filmy fern of eastern North America Trichomanes intricatum Hymenophyllaceae has the chloroplast genome of an Asian species. American Journal of Botany , 95 1645 1651. 2008. Category Trichomanes Category Ferns of the United States Category Flora of the Eastern United States ... more details
Matrotrophy is a form of development in which the embryo is supplied with additional nutrition from the mother e.g. through a placenta . This can be contrasted with lecithotrophy , in which the only source of nutrition for the embryo is yolk originally contained within its Egg biology egg . In plant sciences, matrotrophy maternal care is considered a critical innovation preceding the origin of embryophytes and thus essential to the evolution of land plants ref Graham LKE, Wilcox LW. 2000. The origin of alternation of generations in land plants a focus on matrotrophy and hexose transport. Philosophical transactions of the Royal Society of London B355. 757 67. ref . Matrotrophy is facilitated by cytological and ultrastructural modifications on one or both sides of the generational junction, a region called the placenta ref Ligrone R, Duckett JG, Renzaglia KS. 1993. The gametophyte sporophyte junction in land plants. Advances in botanical research 19. 231 317. ref . Specialization of the placental cells pertains further to their cytological and ultrastructural characteristics the cytoplasm is often dense and rich in lipids, the vacuole is typically reduced but large in Sphagnum, the endoplasmic reticulum extensive, mitochondria numerous and large, chloroplasts numerous, often less differentiated, rich in lipid filled globuli and sometimes filled with starch ref Ligrone R, Duckett JG, Renzaglia KS. 1993. The gametophyte sporophyte junction in land plants. Advances in botanical research 19. 231 317. ref . References references Goffinet B, Et al. 2009. Morphology and classification of Bryophyta. In Bryophyte Biology 2nd ed. Cambridge University Press. Category Embryology botany stub ... more details
of generations between a diploid sporophyte bottom and a haploid gametophyte top Alternation ... gametophyte , which is haploid with N unpaired chromosomes. A mature sporophyte produces .... Spores germinate and grow into a gametophyte. At maturity, the gametophyte produces gamete s by mitosis ... into a diploid sporophyte. This cycle, from sporophyte to sporophyte or equally from gametophyte to gametophyte , is the way in which all land plants and many algae undergo sexual reproduction . The relationship between the sporophyte and gametophyte varies among different groups of plants. In those alga e which have alternation of generations, the sporophyte and gametophyte are separate independent ... s, the sporophyte is less well developed than the gametophyte, being entirely dependent on it in the first two groups. By contrast, the fern gametophyte is less well developed than the sporophyte, forming a small flattened thallus . In flowering plant s, the reduction of the gametophyte is even ... are produced, so neither is a haploid gametophyte. There is no alternation between diploid and haploid ... gametophyte. However, in other species, either the sporophyte or the gametophyte is very much reduced and is incapable of free living. For example, in seed plant s, the gametophyte generation ... the notion of two generations is less obvious as Bateman & Dimichele say s porophyte and gametophyte ... organism, called the gametophyte because at maturity it produces gametes . When it reaches maturity, the gametophyte produces one or more gametangia singular gametangium which are the organs that produce ... 4 crop.jpg thumb Gametophyte of the fern Onoclea sensibilis the flat thallus at the bottom of the picture ... and the gametophyte. Equal homomorphy or isomorphy . br Filamentous algae of the genus Cladophora ... . Image Mnium hornum 2005.04.02 14.55.41.jpg thumb Gametophyte of Mnium hornum , a moss. Dominant gametophyte gametophytic . br In liverworts, mosses and hornworts, the dominant form is the haploid ... more details
ferns. Gametophyte The gametophyte of Psilotum nudum L. Beauv. P. triquetrum Swartz is unusual ... Holloway, J.E. 1939 The gametophyte, embryo and young rhizome of Psilotum triquetrum Schwarz. Annals of Botany 3, 313 336 ref The nutrition of the gametophyte appears to be myco heterotrophs myco ... more details
Unreferenced date December 2009 In biology , a microspore is a small spore as contrasted to the larger megaspore . In botany, microspores develop into male gametophyte s, whereas megaspores develop into female gametophytes. The combination of megaspores and microspores is found only in heterosporous organisms. In seed plant s the microspores give rise to the pollen grains, and the megaspores are formed within the developing seed. Most plant s that reproduce by spore without seed only produce one class of spore. In the fern s, the only heterosporous plants are aquatic or semi aquatic, including the genera Marsilea , Regnellidium , Pilularia , Salvinia , and Azolla . This condition is also known in the lycopod genus Selaginella and in the quillwort genus Iso tes . In zoology, the small swarm spores of Sarcodina are called microspores. Botany stub Category Plant reproduction ca Micr spora es Micr spora fr Microspore gl Microspora hy it Microspora sr ... more details
Taxobox image Pellia epiphylla5 ies.jpg image width 240px regnum Plant ae divisio Marchantiophyta classis Jungermanniopsida ordo Metzgeriales familia Pelliaceae genus Pellia genus authority Raddi, 1818 nom. cons. subdivision ranks Species subdivision See text. synonyms Papa Scopulina Pellia is a small but widespread genus of liverworts in the cool and temperate regions of the northern hemisphere. It is classified in Order biology order Metzgeriales and is a member of the Family biology family Pelliaceae within that order. S sswassertang , a plant grown submerged in aquarium aquaria was once considered to be Pellia endiviifolia , but is now known to be the indeterminate gametophyte of a Lomariopsis species, a type of fern . Species in Pellia Pellia borealis Pellia columbiana Pellia endiviifolia Pellia epiphylla Pellia megaspora Pellia neesiana Bryophyte stub Category Metzgeriales de Pellia fi Lapasammalet ... more details
A megaspore mother cell is a Ploidy diploid cell in which meiosis will occur, resulting in the production of four megaspore s. ref Solomon, Eldra P., 2005, Biology , Thomson, Brooks Cole, United States ref This megasporcyte is formed from two distinct processes megasporogenesis and megagametogenesis. ref name Raven Raven, Peter H., 2005, Biology of Plants , W.H. Freeman and Company Publishers, United States ref Within each sporangium , meiosis of a megaspore mother cell produces four Diploidy Haploid and monoploid haploid megaspores. ref name Raven In gymnosperms and angiosperms , only one of these four megaspores is functional and the other three soon degenerate. The megaspore that remains divides Mitosis mitotically and develops into the female gametophyte, which eventually produces Egg biology eggs . ref name Raven References references Category Plant cells ... more details
for the gametophyte. ref See e.g. Harvnb Taylor Eppley Jesson 2007 . ref Bryophyte sexuality Bryophyte s have life cycles that are gametophyte dominated. The longer lived, more prominent autotrophic plant is the gametophyte. The typical sporophyte in bryophytes is nutritionally dependent on the gametophyte ... more details
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 plants. Eudicots In eudicot plants, the entire process happens inside the ovule of a plant. The details of the process vary by species, but the process described here is common. This process starts with a single diploid megasporocyte in the nucleus. This megasporocyte undergoes meiotic cell division to form four cells that are haploid . Three cells die and one that is most distant from the micropyle develops into the megaspore. This megaspore becomes larger and the nucleus of it undergoes mitosis three times until there are eight nuclei. These eight nuclei are then arranged into two groups of four. These groups both send a nucleus to the center of the cell which then becomes the polar nuclei. The three cells left at the end of the cell near the micropylar become the egg apparatus with an egg cell in the center and two synergids. A cell wall forms around the other set of nuclei and forms the antipodals. The cells in the center develop into the central cell. This entire structure with its eight nuclei is called the embryo sac. Monocots Empty section date July 2010 See also Megaspore it is the female part of the flower in which seeds are formed. it consists of 7 parts funicle, hilam, integuments, micropyle, chalaza, nucellus, embryosac Microspore it is the male part of the flower in which pollen grains are stored. Gametophyte References Reflist 2 Raven,Peter H., Evert, Ray F., Eichhorn, Susan E. 2005 . Biology of Plants, 7th Edition . W. H. Freeman Chapter 19 442 449. Category Reproduction botany stub ... more details
italic title Taxobox name Killarney Fern image Trichomanes speciosum Moore48.png regnum Plant ae divisio Tracheobionta classis Fern Pteridophyta subclassis ordo Hymenophyllales familia Hymenophyllaceae genus Trichomanes species T. speciosum binomial Trichomanes speciosum binomial authority Willd. Trichomanes speciosum commonly known as Killarney Fern is a species of fern found widely in Western Europe . It is most abundant in Ireland , the United Kingdom , Brittany and Canary Islands , Madeira and the Azores , but is also found in other locations including France , Spain , Portugal and Italy . ref http www.ukbap.org.uk UKPlans.aspx?ID 615 Species Action Plan Killarney Fern Trichomanes speciosum BAP. Retrieved 26 June 2008. ref The sporophyte form is found in only 16 locations in the UK although the gametophyte form is more widespread. Once found on Isle of Arran Arran , it was thought to be extinct in Scotland due to the activities of Pteridomania Victorian collectors , ref Ratcliffe, Derek 1977 Highland Flora . Inverness. HIDB. page 40. ref but the species has been discovered on Skye in its gametophyte form. ref http www.plant identification.co.uk skye index.htm Skye Flora . plant identification.co.uk. Retrieved 25 May 2008. ref In the UK it is classed as Vulnerable species vulnerable and it is considered one of Europe s most threatened plants. ref http www.english nature.org.uk science srp rare ferns.htm Species Recovery Programme English Nature. Retrieved 26 June 2008. ref It is one of only three European species with translucent leaves and requires a humid, frost free environment. In Britain, it is largely restricted to damp, shady, sheltered locations such as ravines. ref http www.arkive.org species ARK plants and algae Trichomanes speciosum more info.html?section description Killarney fern Trichomanes speciosum Arkive. Retrieved 26 June 2008. ref References references commonscat Trichomanes speciosum External links http www.habitas.org.uk flora species.asp?ite ... more details
Orphan date January 2009 Taxobox name Sciadophyton image image caption regnum Plant ae divisio classis ordo familia genus Sciadophyton species binomial binomial authority Sciadophyton is a morphotaxon of lower Devonian plants known only from compression fossils. ref name Remyetal1980 cite journal year 1980 author Remy, W Remy, R Hass, H Schultke, S Franzmeyer, F title Sciadophyton Steinmann ein Gametophyt aus dem Siegen. volume 6 pages 37 72 journal Argumenta Palaeobotanica ref ref name Taylor2005 cite journal doi 10.1073 pnas.0501985102 year 2005 month Apr author Taylor, Tn Kerp, H Hass, H title Life history biology of early land plants deciphering the gametophyte phase volume 102 issue 16 pages 5892 7 issn 0027 8424 pmid 15809414 pmc 556298 journal Proceedings of the National Academy of Sciences of the United States of America url http www.pnas.org cgi pmidlookup?view long&pmid 15809414 format Free full text ref It is interpreted as the monoicous gametophyte of a vascular land plant, because its vascularised branches end in a cup shaped structure bearing gametangia, both antheridia and archegonia ref name Kenrick1997 cite book year 1997 author Kenrick, P Crane, PR title The origin and early diversification of land plants A cladistic study. publisher Smithsonian Institution Press, Washington DC ref , but little structural information is preserved at the cellular level. It formed rosettes of stems, which may have radiated from a basal gametophytic corm like thallus or from a central stem or even from a root system, although there is not enough evidence to discriminate between these possibilities. ref name Taylor2005 References reflist Category Devonian life paleobotany stub it Sciadophyton ... more details
Automatic taxobox authority Karl Ritter von Goebel Goebel , 1890 nom. cons. subdivision Treubia insignis br Treubia lacunosa br Treubia pygmaea br Treubia scapanioides br Treubia tahitensis br Treubia tasmanica Treubia is a genus of Marchantiophyta liverworts in the Family biology family Treubiaceae . ref Crandall Stotler, Barbara. & Stotler, Raymond E. 2000 . Morphology and classification of the Marchantiophyta . pages 21 70 in A. Jonathan Shaw & Bernard Goffinet eds. , Bryophyte Biology . Cambridge Cambridge University Press . ISBN 0 521 66097 1 ref There are six species, all of which are restricted to the southern hemisphere. Five of the species occur in Australasia ref name Schuster 1992 cite book last Schuster first Rudolf M. year 1992 title The Hepaticae and Anthocerotae of North America edition Volume 5 pages 332 333 isbn 0 914868 20 9 ref and the other Treubia scapanioides occurs in Chile . All species are dioicous , with separate male and female gametophyte s. References Reflist 2 Category Liverworts Bryophyte stub ... more details
Non vascular plants is a general term for those plant s without a vascular tissue vascular system xylem and phloem . Although non vascular plants lack these particular tissues, a number of non vascular plants possess tissues specialized for internal transport of water . Non vascular plants do not have a wide variety of specialized tissue. Marchantiophyta Liverworts have structures that look like leaf leaves , but they are not true leaves because they have no xylem or phloem . Likewise, mosses and algae have no such tissues. All plants have a life cycle with an alternation of generations between a diploid sporophyte and a haploid gametophyte , but only nonvascular plants can potentially have a dominant gametophyte generation. In these plants, the sporophytes grow from and are dependent on gametophytes for taking in water and other materials. Non vascular groups The term non vascular plant is no longer used in scientific nomenclature. Non vascular plants include two distantly related groups Bryophyte s moss Bryophyta mosses , Marchantiophyta liverworts , and hornwort Anthocerotophyta hornworts . In these groups, the primary plants are the haploid gametophyte s, with the only diploid portion being the attached sporophyte , consisting of a stalk and sporangium . Because these plants lack water conducting tissues, they can t become as tall as most vascular plant s. Alga e especially the green algae . Recent studies have demonstrated that the algae actually consist of several unrelated groups. It turns out that common features of living in water and photosynthesis were misleading as indicators of close relationship. Only the Archaeplastida are still considered relatives of the plants. Both of these groups are occasionally termed the lower plants the term lower refers to these plants status as the earliest plants to evolution evolve . However, the term lower plants is not precise, since it frequently is used to include some Vascular tissue vascular plants, the fern s and f ... more details
italic title Taxobox name Schmitzia hiscockiana image image width 250px image caption color lightgreen regnum Protoctista phylum Red algae Rhodophyta classis Florideophyceae ordo Gigartinales familia Calosiphoniaceae genus Schmitzia species S. hiscockiana binomial Schmitzia hiscockiana binomial authority Maggs & Guiry Schmitzia hiscockiana Maggs & Guiry is a small, rare, red seaweed or marine ocean marine alga of the phylum Rhodophyta or red algae. It was discovered and named in 1985. Distribution This small red marine alga is known from most coasts of Ireland , Wales , England , and Scandinavia ref http www.algaebase.org search species detail ?species id 116 ref . Habitat This species is known only from the sublittoral zone to 15m depth it grows on cobbles and pebbles. The gametophyte plants exist between April and August, and are in the crustose phase from September to December. Species description The gametophyte phase is a soft and gelatinous plant, no more than 8 cm long, 6 cm wide and a few millimeters thick. It is flattened and divided in a leaf like manner with marginal proliferations. Rose pink in colour, the blades are composed of a filamentous axis bearing whorls of branchlets, four or five per axial cell. These whorls of branchlets form a cortex. Life history The plants are monoecious, bearing spermatia and carpogonia. After fertilization and development of connecting filaments and fusion with intercalary vegetative cells, a carposporphyte develops. The tetrasporophyte phase is crustose and unknown in the wild. ref Hardy, F.G. and Guiry, M.D. 2006. A Check list and Atlas of the Seaweeds of Britain and Ireland. British Phycological Society, London. ISBN 3 906166 35 X ref It is bright red and grows to 6 mm in diameter and composed of a single basal layer of cells which produce erect filaments some of which produce tetraspores. These tetraspores develop and grow to give rise to the gametophyte generations. ref Maggs, C.A. and Guiry, M.D. 1985. Life history ... more details
taxobox image Myriotrichia.jpg image caption The gametophyte of M. clavaeformis . Click image for explanation of labelling. regnum Chromalveolata divisio Heterokontophyta classis Brown algae Phaeophyceae ordo Ectocarpales familia Chordariaceae genus Myriotrichia subdivision ranks Species subdivision M. adriatica M. canariensis M. clavaeformis formerly M. repens M. densa M. filiformis M. harveyana M. occidentalis M. protasperococcus M. scutata M. subcorymbosa ref http nomen.at Myriotrichia Myriotrichia Nomen.at animals and plants Bot generated title ref Orphan date June 2008 Myriotrichia is a genus of brown alga. ref Cite journal title Morphologie und biologie der Algen author Oltmanns, Freidrich volume 1 language German year 1904 postscript None ref It forms small, soft, olive brown tufts wict epiphyte on the surface of other plants . Filaments rarely exceed centimetres in length. ref name Fritsch1945 Cite document author F. E. Fritsch authorlink Felix Eugen Fritsch year 1945 title The Structure and Reproduction of the Algae. volume II publisher Cambridge University Press location Cambridge, England postscript None ref Rp 105 It may grow by intercalary growth. ref name Fritsch1945 rp 105 Its sporangia may contain one or many cavities, and emerge directly from the surface cells they may form a ring around the main wict nema . ref name Fritsch1945 rp 105 Dedicated photosynthetic machinery may be entirely absent. ref name Fritsch1945 rp 107 Its life history consists of alternation of phases it has isogamous gametes, and dioecious gametophytes. ref name Peters2004 cite journal author Peters, Akira F. Marie, Dominique Scornet, Delphine Kloareg, Bernard Mark Cock, J. year 2004 doi 10.1111 j.1529 8817.2004.04058.x title Proposal Of Ectocarpus Siliculosus Ectocarpales, Phaeophyceae ... in multi chambered mitosporangia . ref name Peters2004 The gametophyte phase only produces gametes ... Journal of Phycology volume 27 pages 177 issue 2 ref The gametophyte is filamentous while the sporophyte ... more details
name YadegariaDrews cite journal title Female Gametophyte Development journal The Plant Cell date ... then undergoes megagametogenesis to give rise to the female gametophyte . Megagametogenesis After megasporogenesis, the megaspore develops into the female gametophyte the embryo sac in a process called ... more details
phases , a gametophyte and a sporophyte. The gametophyte is the multicellular structure plant that is haploid , containing a single set of chromosome s in each cell. The gametophyte produces ... pairs are separated once again to form single sets. In mosses and liverworts the gametophyte is relatively large, and the sporophyte is a much smaller structure that is never separated from the gametophyte ... reproductive organs called flowers, with carpel s, and the female gametophyte is greatly reduced to a female embryo sac, with as few as eight cells. The male gametophyte consists of the pollen grains ... anther produces male gametophyte s, the sperm is produced in pollen pollen grains , which attach ... into the ovule to fertilize the egg cell and endosperm nuclei within the female gametophyte in a process ... tissues in the developing seed. The ovary, which produced the female gametophyte s , then grows ... into a new sporophytic plant. The condition of having separate sporephyte and gametophyte plants ... . The gametophyte is the most commonly known phase of the plant. An early developmental stage in the gametophyte of mosses immediately following germination of the meiospore is called the protonema ... more details
related to double fertilization Megagametophyte The female gametophyte , or megagametophyte, used ... then divide this mass into a muticellular female gametophyte , called the embryo sac. The lower end ... sac, rather than being partitioned into separate cells. Microgametophyte The male gametophyte ... gametophyte matures, the generative cell passes into the tube cell, and the tube cell produces the pollen ... more details
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