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Porina Howeana
''Porina howeana'' is a species of saxicolous (rock-dwelling) crustose lichen in the family Trichotheliaceae. Found on Lord Howe Island, Australia, it was formally described as a new species in 1997 by lichenologist Patrick M. McCarthy. The type specimen was collected by the author from east of Dawsons Point Ridge on Max Nicholls Track, where it was growing on shaded basalt. Description It has a olivaceous-brown, usually glossy thallus, lacking both a cortex and a prothallus. The photobiont partner is a green alga from the genus '' Trentepohlia'', with cells that measure 6–12 by 6–10 μm. Characters that distinguish it from other members of genus ''Porina ''Porina'' is a genus of lichens in the family Trichotheliaceae. A 2020 estimate places about 145 species in the widespread genus. Species *''Porina abrupta'' *'' Porina adflata'' *'' Porina africana'' *'' Porina ahlesiana'' *'' Porina ...'' include its outwardly blackish that is dark orange-b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saxicolous Lichen
A saxicolous lichen is a lichen that grows on rock. The prefix "sax" from the Latin means "rock" or "stone". Characteristics Saxicolous lichens exhibit very slow growth rates. They may develop on rock substrates for long periods of time, given the absence of external disturbances. The importance of the mineral composition of the rock substrate, as well as the elemental geochemistry Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ... is also important to the distribution of saxicolous lichens, but the relationship between the substrate influence on lichens, either chemical or textural, is still obscure. Communities of saxicolous lichens are often species-rich in terms of number. References Lichenology {{lichen-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photobiont
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Lichen Species
A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Introduction to Lichens – An Alliance between Kingdoms . University of California Museum of Paleontology. Lichens have properties different from those of their component organisms. They come in many colors, sizes, and forms and are sometimes plant-like, but are not s. They may have tiny, leafless branches (); flat leaf-like structures ( |
Gyalectales
''Gyalectales'' is an order of lichen-forming fungi in the class Lecanoromycetes. It contains 5 families, 15 genera and about 550 species. Taxonomy The Gyalectales were introduced in a 1974 publication by Aino Henssen and Martin Jahns, but not formally published until 1986 by David Hawksworth and Ove Eriksson. Phylogeny An early (2002) phylogenetics study showed that the order Ostropales, as was then circumscribed, was paraphyletic, and proposed that the Ostropales sensu lato included the Gyalectales and Trapeliaceae. Although they had traditionally been considered to be only distantly related, molecular studies suggested a much closer phylogenetic relationship. As a result, of the molecular data, Kauff and Lutzoni subsumed the Gyalectales into the Ostropales, as the latter name was published earlier (1932 vs. 1986). In 2018, Kraichak and colleagues used a recently developed "temporal phylogenetic" approach to identify temporal bands for specific taxonomic ranks. Base ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascospore
An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or species can occur in numbers of one (e.g. ''Monosporascus cannonballus''), two, four, or multiples of four. In a few cases, the ascospores can bud off conidia that may fill the asci (e.g. ''Tympanis'') with hundreds of conidia, or the ascospores may fragment, e.g. some ''Cordyceps'', also filling the asci with smaller cells. Ascospores are nonmotile, usually single celled, but not infrequently may be coenocytic (lacking a septum), and in some cases coenocytic in multiple planes. Mitotic divisions within the developing spores populate each resulting cell in septate ascospores with nuclei. The term ocular chamber, or oculus, refers to the epiplasm (the portion of cytoplasm not used in ascospore formation) that is surrounded by the "bourrelet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Porina
''Porina'' is a genus of lichens in the family Trichotheliaceae. A 2020 estimate places about 145 species in the widespread genus. Species *''Porina abrupta'' *'' Porina adflata'' *'' Porina africana'' *'' Porina ahlesiana'' *'' Porina alba'' *'' Porina albicera'' *''Porina albida'' *'' Porina aluniticola'' *''Porina aptrootii'' *''Porina arnoldii'' *''Porina athertonii'' *'' Porina atlantica'' *'' Porina atriceps'' *'' Porina atropunctata'' *''Porina australiensis'' *''Porina australis'' *''Porina austroatlantica'' *''Porina austropacifica'' *''Porina bacillifera'' *''Porina barbifera'' *''Porina bellendenica'' *''Porina biroi'' *''Porina blechnicola'' *''Porina boliviana'' *'' Porina bonplandii'' *'' Porina bryophila'' *'' Porina canthicarpa'' *'' Porina chloroticula'' *'' Porina chrysophora'' *'' Porina coarctata'' *'' Porina conica'' *'' Porina constrictospora'' – Australia *'' Porina coralloidea'' *''Porina corrugata'' *''Porina crassa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometre
The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Units (SI) equalling (SI standard prefix "micro-" = ); that is, one millionth of a metre (or one thousandth of a millimetre, , or about ). The nearest smaller common SI unit is the nanometre, equivalent to one thousandth of a micrometre, one millionth of a millimetre or one billionth of a metre (). The micrometre is a common unit of measurement for wavelengths of infrared radiation as well as sizes of biological cells and bacteria, and for grading wool by the diameter of the fibres. The width of a single human hair ranges from approximately 20 to . The longest human chromosome, chromosome 1, is approximately in length. Examples Between 1 μm and 10 μm: * 1–10 μm – length of a typical bacterium * 3–8 μm – width of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trentepohlia (alga)
''Trentepohlia'' is a genus of filamentous chlorophyte green algae in the family Trentepohliaceae, living free on terrestrial supports such as tree trunks and wet rocks or symbiotically in lichens. The filaments of ''Trentepohlia'' have a strong orange colour (photograph at right) caused by the presence of large quantities of carotenoid pigments which mask the green of the chlorophyll. ''Trentepohlia'' species form associations with fungal hyphae, and are widespread phycobionts in lichens, such as the "secret writing" crustose lichen genera '' Graphis'', ''Graphina'', ''Gyalecta'' and ''Opegrapha''.F.S. Dobson (2000) Lichens, an illustrated guide to the British and Irish species. Richmond publishing Co. T. Friedl and B. Büdel (1996) Photobionts, in Nash, T.H. (ed.) Lichen biology, pp.8-23, Cambridge University Press. There are about 40 species of ''Trentepohlia'' mostly distributed in tropical and subtropical areas but several species also occur in temperate environments inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Alga
The green algae (singular: green alga) are a group consisting of the Prasinodermophyta and its unnamed sister which contains the Chlorophyta and Charophyta/Streptophyta. The land plants (Embryophytes) have emerged deep in the Charophyte alga as sister of the Zygnematophyceae. Since the realization that the Embryophytes emerged within the green algae, some authors are starting to properly include them. The completed clade that includes both green algae and embryophytes is monophyletic and is referred to as the clade Viridiplantae and as the kingdom Plantae. The green algae include unicellular and colonial flagellates, most with two flagella per cell, as well as various colonial, coccoid and filamentous forms, and macroscopic, multicellular seaweeds. There are about 22,000 species of green algae. Many species live most of their lives as single cells, while other species form coenobia (colonies), long filaments, or highly differentiated macroscopic seaweeds. A few other organ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prothallus
A prothallus, or prothallium, (from Latin ''pro'' = forwards and Greek ''θαλλος'' (''thallos'') = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young gametophyte of a liverwort or peat moss as well. In lichens it refers to the region of the thallus that is free of algae. The prothallus develops from a germinating spore. It is a short-lived and inconspicuous heart-shaped structure typically 2–5 millimeters wide, with a number of rhizoids (root-like hairs) growing underneath, and the sex organs: archegonium (female) and antheridium (male). Appearance varies quite a lot between species. Some are green and conduct photosynthesis while others are colorless and nourish themselves underground as saprotrophs. Alternation of generations Spore-bearing plants, like all plants, go through a life-cycle of alternation of generations. The fully grown sporophyte, what is commonly referred to as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crustose Lichen
Crustose lichens are lichens that form a crust which strongly adheres to the Substrate (biology), substrate (soil, rock, tree bark, etc.), making separation from the substrate impossible without destruction. The basic structure of crustose lichens consists of a cortex (botany), cortex layer, an algal layer, and a medulla. The upper cortex layer is differentiated and is usually pigmented. The algal layer lies beneath the cortex. The medulla fastens the lichen to the substrate and is made up of Fungus, fungal hyphae. The surface of crustose lichens is characterized by branching cracks that periodically close in response to climatic variations such as alternate wetting and drying regimes. Subtypes * Powdery – considered as the simplest subtype due to the absence of an organized thallus. :The thallus appears powdery. :E.g. Genera ''Lepraria'', ''Vezdaea'' * Endolithic – grows inside the rock, usually in interstitial spaces between mineral grains. The :upper cortex is usually d ... [...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 als ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
