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Ceratopteris
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Oblongiloba
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Cornuta In Detail (emerse)
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Cornuta
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Froesii
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Gaudichaudii
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Pteridoides
''Ceratopteris'' is the only genus among homosporous ferns that is exclusively aquatic. It is pan-tropical and classified in the Parkerioideae subfamily of the family Pteridaceae. Description Erect aquatic or subaquatic ferns of moderate size. Rhizome short, fleshy, horizontal and ascending to erect, loosely rooted in the mud or +/- floating, radial, dictyostelic with numerous meristeles and medullary strands, young parts bearing thin, ovate, +/- cordate, clathrate scales. Fronds stipitate, the stipes fleshy, with numerous longitudinal air canals, abaxially rounded and ribbed, adaxially flattened, vascular bundles in a peripheral ring, one with each rib and several to the adaxial side, and several smaller medullary strands; lamina dimorphic, sterile fronds +/- spreading, 2–3-pinnatifid with broad membranous lobes, venation reticulate without included free veinlets, often with proliferous buds in the axils; fertile fronds erect, longer, narrower and more divided than the steril ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Thalictroides
''Ceratopteris thalictroides'' is a fern species belonging to the genus '' Ceratopteris'', one of only two genera of the subfamily Parkerioideae of the family Pteridaceae. Common names ''Ceratopteris thalictroides'' is commonly known as water sprite, Indian fern, water fern, oriental waterfern, and water hornfern. In the Philippines, it is called ''pakung-sungay'' (literally 'antler fern' or 'horn fern'). Distribution ''Ceratopteris thalictroides'' is widespread across tropical regions. Description Rooted in mud, ''Ceratopteris thalictroides'' plants vary in size and appearance. The stipes of mature plants are 3-15 mm in diameter, spongy, and air-filled with long including its stipe. Pale green, brown when matured, fertile fronds are or more, including the stipe, to long. Proliferous or dormant buds with their overlapping dark scales present in the axils of fertile pinnae are winged. Pinnae are deeply incised with segments 2-15 mm x 10-30 mm and the fertile segments 1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ceratopteris Richardii
''Ceratopteris richardii'' is a fern species belonging to the genus ''Ceratopteris'', one of only two genera of the subfamily Parkerioideae of the family Pteridaceae. It is one of several genera of ferns adapted to an aquatic existence. ''C. richardii'' was previously regarded as being part of the species ''Ceratopteris thalictroides''. "C-Fern" This particular species is of special scientific interest because a patented strain, called "C-Fern", was developed as a scientific aid and teaching tool in biology in 1995. The use of "C-Fern" is facilitated by the fact that it grows readily in a cell-culture dish on agar media, reaching sexual maturity within 2–3 weeks of spore inoculation, with motile sperm cells being visible at this time. Over the course of about 6 weeks germination, sex determination and development of gametophytes, fertilization, embryogenesis, organogenesis, and sporophyte growth can all be observed, allowing an incredibly comprehensive study of the life cyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pteridaceae
Pteridaceae is a family of ferns in the order Polypodiales, including some 1150 known species in ca 45 genera (depending on taxonomic opinions), divided over five subfamilies. The family includes four groups of genera that are sometimes recognized as separate families: the adiantoid, cheilanthoid, pteridoid, and hemionitidoid ferns. Relationships among these groups remain unclear, and although some recent genetic analyses of the Pteridales suggest that neither the family Pteridaceae nor the major groups within it are all monophyletic, as yet these analyses are insufficiently comprehensive and robust to provide good support for a revision of the order at the family level. Description Members of Pteridaceae have creeping or erect rhizomes. The leaves are almost always compound and have linear sori that are typically on the margins of the leaves and lack a true indusium, typically being protected by a false indusium formed from the reflexed margin of the leaf. Taxonomy Tradi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parkerioideae
Parkerioideae, Synonym (taxonomy), synonym Ceratopteridoideae, is one of the five subfamilies in the fern family Pteridaceae. It includes only the two genera ''Acrostichum'' and ''Ceratopteris''. The following diagram shows a likely phylogenic relationship between the two Parkerioideae genera and the other Pteridaceae subfamilies. References Pteridaceae Plant subfamilies {{Pteridaceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antheridiogen
Antheridiogens are a class of chemicals secreted by fern gametophytes that have "been shown to influence production of male gametangia and thus mating systems in a large number of terrestrial fern species". Antheridiogens are only observed in homosporous fern species, as all gametophytes are potentially bisexual (have the ability to produce both archegonia and antheridia). Background The first study regarding antheridiogen was published by Walter Döpp in 1950. In this article, he explains the discovery of a molecule, which he titled "A-substanz", that caused premature formation of antheridia when agar media was reused after cultivation of ''Pteridium aquilinum.'' A majority of the studies regarding antheridiogen were done by two researchers, Ulrich Näf and H. Schraudolf. Sex-determination pathway The way in which antheridiogen determines sex in ferns is a "spatiotemporally split gibberellin synthesis pathway". Gibberellin is a group of hormones that control plant processes. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrostichum
''Acrostichum'' is a fern genus in the Parkerioideae subfamily of the Pteridaceae. It was one of the original pteridophyte genera delineated by Linnaeus. It was originally drawn very broadly, including all ferns that had sori apparently "acrostichoid", or distributed in a uniform mass across the back of the frond, rather than organized in discrete sori. This led Linnaeus to include such species as ''Asplenium platyneuron'' in the genus, because the specimen he received had sori so crowded that it appeared acrostichoid. Since '' Acrostichum aureum'' is regarded as the type for the genus, it is now narrowly circumscribed only to the natural genus of three species, that are allied to the genus '' Ceratopteris''. They are collectively known as the leather ferns or leather swamp ferns, genus members commonly being found in swamps. The species of ''Acrostichum'' are massive ferns, with fronds up to 12 feet (3.5 meters) tall, that depend on a semi-aquatic existence. They do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
