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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 surroundi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Alga
Brown algae (singular: alga), comprising the class Phaeophyceae, are a large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Brown algae are the major seaweeds of the temperate and polar regions. They are dominant on rocky shores throughout cooler areas of the world. Most brown algae live in marine environments, where they play an important role both as food and as a potential habitat. For instance, ''Macrocystis'', a kelp of the order Laminariales, may reach in length and forms prominent underwater kelp forests. Kelp forests like these contain a high level of biodiversity. Another example is ''Sargassum'', which creates unique floating mats of seaweed in the tropical waters of the Sargasso Sea that serve as the habitats for many species. Many brown algae, such as members of the order Fucales, commonly grow along rocky seashores. Some members of the class, such as kelps, are used by humans as food. Between 1,500 ... [...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 conceptacle ... [...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 tetraspore Tetraspores are red algae spores produced by the tetrasporophytic (diploid) phase in the life history of algae in the Rhodophyta as a result of meiosis.Jones, W.E. Revised and reprinted 1964. A Key to the genera of the British seaweeds.''Field Stu ...s 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'', with many ''Hildenbrandia'' species being recognized as non-monop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hildenbrandiales
Hildenbrandiales is an order of crustose forms red alga which bear conceptacles and produce secondary pit-connections. They reproduce by vegetative gemma (botany), 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'', with many ''Hildenbrandia'' species being recognized as non-monophyletic. References Florideophyceae Red algae orders {{Rhodophyta-stub ... [...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 avail ... Corallinaceae Red algae genera {{Rhodophyta-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptacle (botany)
In botany, the receptacle refers to vegetative tissues near the end of reproductive stems that are situated below or encase the reproductive organs. Angiosperms In angiosperms, the receptacle or torus (an older term is thalamus, as in Thalamiflorae) is the thickened part of a stem (pedicel) from which the flower organs grow. In some accessory fruits, for example the pome and strawberry, the receptacle gives rise to the edible part of the fruit. The fruit of ''Rubus'' species is a cluster of drupelets on top of a conical receptacle. When a raspberry is picked, the receptacle separates from the fruit, but in blackberries, it remains attached to the fruit. — In the Daisy family (Compositae or Asteraceae), small individual flowers are arranged on a round or dome-like structure that is also called receptacle. Algae and bryophyta In phycology, receptacles occur at the ends of branches of algae mainly in the brown algae or Heterokontophyta in the Order Fucales. They are s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perithallus
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Corallines
Coralline algae are red algae in the order Corallinales. They are characterized by a thallus that is hard because of calcareous deposits contained within the cell walls. The colors of these algae are most typically pink, or some other shade of red, but some species can be purple, yellow, blue, white, or gray-green. Coralline algae play an important role in the ecology of coral reefs. Sea urchins, parrot fish, and limpets and chitons (both mollusks) feed on coralline algae. In the temperate Mediterranean Sea, coralline algae are the main builders of a typical algal reef, the ''Coralligène'' ("coralligenous"). Many are typically encrusting and rock-like, found in marine waters all over the world. Only one species lives in freshwater. Unattached specimens ( maerl, rhodoliths) may form relatively smooth compact balls to warty or fruticose thalli. A close look at almost any intertidal rocky shore or coral reef will reveal an abundance of pink to pinkish-grey patches, distributed th ... [...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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 carpospore A carpospore is a diploid spore produced by red algae. After fertilization, the alga's carpogonium The carpogonium (plural ''carpogonia'') is the female organ in the Red Algae (Rhodophyta) which have a highly specialized type of reproduction. It c ...s 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] |
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 ... [...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 Museum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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