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Conceptacle
Conceptacles are specialized cavities of marine and freshwater algae that contain the reproductive organs. They are situated in the receptacle and open by a small ostiole.Boney, A.D. (1969). ''A Biology of Marine Algae''. Hutchinson Educational Ltd, London Conceptacles are present in Corallinaceae,Irvine, L.M. and Chamberlain, Y.M. (1994). ''Seaweeds of the British Isles''. Volume 1, Part 2B. Natural History Museum, London. and Hildenbrandiales, as well as the brown Fucales. In the Fucales there is no haploid phase in the reproductive cycle and therefore no alternation of generations.Fritsch, F.E. (1945). ''The Structure and Reproduction of the Algae''. Vol 2. Cambridge University Press, Cambridge The thallus is a sporophyte.Smith, G.M. (1938). ''Cryptogamic Botany. Algae and Fungi''. Second edition, Volume ''1'', McGraw-Hill Bok Company, Inc. The diploid plants produce male (antheridia) and female (oogonia) gametangia by meiosis. The gametes are released into the surrounding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algae
Algae ( , ; : alga ) are any of a large and diverse group of photosynthetic, eukaryotic organisms. The name is an informal term for a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular microalgae, such as '' Chlorella'', '' Prototheca'' and the diatoms, to multicellular forms, such as the giant kelp, a large brown alga which may grow up to in length. Most are aquatic and lack many of the distinct cell and tissue types, such as stomata, xylem and phloem that are found in land plants. The largest and most complex marine algae are called seaweeds, while the most complex freshwater forms are the '' Charophyta'', a division of green algae which includes, for example, '' Spirogyra'' and stoneworts. Algae that are carried by water are plankton, specifically phytoplankton. Algae constitute a polyphyletic group since they do not include a common ancestor, and although their plastids seem to have a single ori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fucus Conceptacle
''Fucus'' is a genus of brown algae found in the intertidal zones of rocky seashores almost throughout the world. Description and life cycle The thallus is perennial with an irregular or disc-shaped holdfast or with haptera. The erect portion of the thallus is dichotomous or subpinnately branched, flattened and with a distinct midrib. Gas-filled pneumatocysts (air- vesicles) are present in pairs in some species, one on either side of the midrib. The erect portion of the thallus bears cryptostomata and caecostomata (sterile surface cavities). The base of the thallus is stipe-like due to abrasion of the tissue lateral to the midrib and it is attached to the rock by a holdfast. The gametangia develop in conceptacles embedded in receptacles in the apices of the final branches. They may be monoecious or dioecious. These algae have a relatively simple life cycle and produce only one type of thallus which grows to a maximum size of 2 m. Fertile cavities, the conceptacles, cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bossiella
''Bossiella'' is a genus of coralline algae with 5 recognised species. It reproduces via conceptacles; individual thalli only produce conceptacles of a single sex. Species The valid species currently considered to belong to this genus are: *'' Bossiella californica'' *'' Bossiella chiloensis'' *'' Bossiella compressa'' *'' Bossiella orbigniana'' *'' Bossiella plumosa'' References * External linksImagesof ''Bossiella'' at Algaebase AlgaeBase is a global species database of information on all groups of algae, both marine and freshwater, as well as sea-grass. History AlgaeBase began in March 1996, founded by Michael Guiry. Text was copied from this source, which is ava ... Corallinaceae Red algae genera {{Rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prototaxites
''Prototaxites'' is a genus of terrestrial fossil fungi dating from the Middle Ordovician until the Late Devonian periods, approximately . ''Prototaxites'' formed small to large trunk-like structures up to wide, reaching in length, made up of interwoven tubes around in diameter, making it by far the largest land-dwelling organism of its time. Whilst traditionally very difficult to assign to an extant group of organisms, current opinion suggests a fungal placement for the genus. Its exact relationship with extant fungus lineages is uncertain. It was almost certainly a perennial organism that grew over multiple years. Several ecologies have been proposed, including that it was saprotrophic like many modern fungi, or that it was a lichenised autotroph. Morphology left, upDawson's 1888 reconstruction of a conifer-like ''Prototaxites'' With a diameter of up to , and a height reaching , ''Prototaxites'' fossils are remnants of by far the largest organism discovered from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reproductive Initials
Reproductive initials are filaments below the cuticle surface of algae and fungi which give rise to the bulbs of spore-producing cells (in fungi, conidiophores A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...). References Algal anatomy {{Alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Epithallium
The epithallium is a layer of many algae which bears the majority of photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in ... apparatus. References Algal anatomy {{alga-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cortex (botany)
In botany, a cortex is an outer layer of a stem or root in a vascular plant, lying below the epidermis but outside of the vascular bundles. The cortex is composed mostly of large thin-walled parenchyma cells of the ground tissue system and shows little to no structural differentiation. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells. Plants Stems and branches In the three dimensional structure of herbaceous stems, the epidermis, cortex and vascular cambium form concentric cylinders around the inner cylindrical core of pith. Some of the outer cortical cells may contain chloroplasts, giving them a green color. They can therefore produce simple carbohydrates through photosynthesis. In woody plants, the cortex is located between the periderm (bark) and the vascular tissue (phloem, in particular). It is responsible for the transportation of materials into the central cylinder of the root through diffusion and may al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medulla
Medulla or Medullary may refer to: Science * Medulla oblongata, a part of the brain stem * Renal medulla, a part of the kidney * Adrenal medulla, a part of the adrenal gland * Medulla of ovary, a stroma in the center of the ovary * Medulla of the thymus, a part of the lobes of the thymus * Medulla of lymph node * Medulla (hair), the innermost layer of the hair shaft * Medulla, a part of the optic lobe of arthropods * Medulla (lichenology), a layer of the internal structure of a lichen * Pith, or medulla, a tissue in the stems of vascular plants Other uses * '' Medúlla'', a 2004 album by Björk * Medulla, Florida, a place in the U.S. * Las Médulas, a gold mining site in León, Spain See also * * Medullary cavity, the central cavity of bone shafts * Medullary ray (other) * ''Medulla Grammatice ''Medulla Grammatice'' or ''Medulla Grammaticae'' ("the Marrow of Grammar") is a collection of fifteenth century Latin–Middle English glossaries in the British Mus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perithallus
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Cystocarp
A cystocarp is the fruiting structure produced in the red algae after fertilization, especially such a structure having a special protective envelope (as in '' Polysiphonia)''. The structure from which carpospores are released.Maggs, C.A. and Hommersand, M.H. 1993. ''Seaweeds of the British Isles Volume 1 Rhodophyta Part 3A Ceramiales.'' The Natural History Museum, London References {{reflist Algal anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fucus Distichus
''Fucus distichus'' or rockweed is a species of brown alga in the family Fucaceae to be found in the intertidal zones of rocky seashores in the Northern Hemisphere, mostly in rock pools. Description This is a small tufted brown alga. The fronds are rarely more than 4 mm wideBunker, F.StP.D., Maggs, C.A., Brodie, J.A. and Bunker, A.R. 2017. ''Seaweeds of Britain and Ireland.'' Second Edition. Wild Nature Press, Plymouth, UK narrow and grow up to thirty centimetres long. They do not include airbladders as in some other species of ''Fucus''. The fronds are fairly rigid and cartilaginous, partially flattened, and olive green to yellowish green in colour. The plant is branched and has a basal discoid holdfast. The midrib is conspicuous and near the holdfast the stalk is narrowed because of the thickening of the midrib and the erosion of the margins. The apices of the frond are rounded and the swollen receptacles at the tips are yellowish and up to six centimetres long. Two su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildenbrandiaceae
Hildenbrandiales is an order of crustose forms red alga which bear conceptacles and produce secondary pit-connections. They reproduce by vegetative gemmae as well as tetrasporangia, which are produced inside the conceptacles. The way in which the tetraspores are produced is unusual enough to justify the formation of this distinct order. Some members of the order are known from freshwater rivers as well . Systematics Hildenbradiales are difficult to discriminate on morphological grounds; tetrasporangia morphology is the only vaguely reliable character, but molecular techniques have indicated a monophyletic '' Apophlaea'' within a paraphyletic ''Hildenbrandia ''Hildenbrandia'' is a genus of thalloid red algae, red alga comprising about 26 species. The slow-growing, non-mineralized thalli take a crustose form. ''Hildenbrandia'' reproduces by means of conceptacles and produces tetraspores. Morphology ...'', with many ''Hildenbrandia'' species being recognized as non-monophylet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
_Powell_-_Fucaceae_-_Plant_type_specimen.jpeg "Click for more on -> Fucus Distichus")