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Quillwort
''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual species often scarce to rare. Some botanists split the genus, separating two South American species into the genus ''Stylites'', although molecular data place these species among other species of ''Isoetes'', so that ''Stylites'' does not warrant taxonomic recognition. Species of ''Isoetes'' virtually identical to modern forms have existed since the Jurassic epoch. The name of the genus may also be spelled ''Isoëtes''. The diaeresis (two dots over the e) indicates that the o and the e are to be pronounced in two distinct syllables. Including this in print is optional; either spelling (''Isoetes'' or ''Isoëtes'') is correct. Description Quillworts are mostly aquatic or semi-aquatic in clear ponds and slow-moving streams, though several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Megasporangia L
''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual species often scarce to rare. Some botanists split the genus, separating two South American species into the genus ''Stylites'', although molecular data place these species among other species of ''Isoetes'', so that ''Stylites'' does not warrant taxonomic recognition. Species of ''Isoetes'' virtually identical to modern forms have existed since the Jurassic epoch. The name of the genus may also be spelled ''Isoëtes''. The diaeresis (two dots over the e) indicates that the o and the e are to be pronounced in two distinct syllables. Including this in print is optional; either spelling (''Isoetes'' or ''Isoëtes'') is correct. Description Quillworts are mostly aquatic or semi-aquatic in clear ponds and slow-moving streams, though several ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Taiwanensis
''Isoetes taiwanensis'' is a species of plant in the family Isoetaceae. It is endemic to Taiwan, and the only species of quillwort there. As other quillworts, it is relatively small, with erect leaves long. It grows submersed in shallow ponds for most of the year. IUCN considers it critically endangered because of habitat loss. The first quillwort genome sequence was of ''I. taiwanensis''. This showed that there were differences in its biochemistry from terrestrial plants that had adopted the same strategy for CO2 fixation, namely Crassulacean acid metabolism (CAM). This involves the enzyme phosphoenolpyruvate carboxylase (PEPC) and plants have two forms of the enzyme. One is normally involved in CO2 fixation during photosynthesis and the other in central metabolism. From the genome sequence, it appears that in ''I. taiwanensis'' both forms are involved in photosynthesis. In addition, the time of day of the peak abundance of some of the components of CAM was different from t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepidodendron
''Lepidodendron'' is an extinct genus of primitive vascular plants belonging to the family Lepidodendraceae, part of a group of Lycopodiopsida known as scale trees or arborescent lycophytes, related to quillworts and lycopsids (club mosses). They were part of the coal forest flora. They sometimes reached heights of , and the trunks were often over in diameter. They thrived during the Carboniferous Period (358.9 to 298.9 million years ago). Sometimes erroneously called "giant club mosses", the genus was actually more closely related to modern quillworts than to modern club mosses. Within the form classification system used within paleobotany, ''Lepidodendron'' is both used for the whole plant as well as specifically the stems and leaves. Etymology The name ''Lepidodendron'' comes from the Greek λεπίς ', scale, and δένδρον ''dendron'', tree. Growth During the early stages of growth, ''Lepidodendron'' grew as single, unbranched trunk, with leaves growing out of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lycopodiopsida
Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching stems bearing simple leaves called microphylls and reproduce by means of spores borne in sporangia on the sides of the stems at the bases of the leaves. Although living species are small, during the Carboniferous, extinct tree-like forms formed huge forests that dominated the landscape and contributed to coal deposits. The nomenclature and classification of plants with microphylls varies substantially among authors. A consensus classification for extant (living) species was produced in 2016 by the Pteridophyte Phylogeny Group (PPG I), which places them all in the class Lycopodiopsida, which includes the classes Isoetopsida and Selaginellopsida used in other systems. (See Table 2.) Alternative classification systems have used ranks f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Nuttallii
''Isoetes nuttallii'', or Nuttall's quillwort, is a species of quillwort, a type of lycopod. It is native to shallow waters and other wet habitats of western North America from British Columbia to California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m .... It produces up to 60 pointed, cylindrical, green to gray-green leaves, each 7 to 17 centimeters long. The velum completely covers the spherical sporangia, which are 5 millimeters long and 1.5 millimeters wide. The ligule is small and triangular. The megaspores are 400 to 500 micrometers in diameter. The microspores, which are spiny and covered in tubercles, are 28 to 31 micrometers long. References External linksJepson Manual Treatment [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crassulacean Acid Metabolism
Crassulacean acid metabolism, also known as CAM photosynthesis, is a carbon fixation pathway that evolved in some plants as an adaptation to arid conditions that allows a plant to photosynthesize during the day, but only exchange gases at night. In a plant using full CAM, the stomata in the leaves remain shut during the day to reduce evapotranspiration, but they open at night to collect carbon dioxide () and allow it to diffuse into the mesophyll cells. The is stored as four-carbon malic acid in vacuoles at night, and then in the daytime, the malate is transported to chloroplasts where it is converted back to , which is then used during photosynthesis. The pre-collected is concentrated around the enzyme RuBisCO, increasing photosynthetic efficiency. This mechanism of acid metabolism was first discovered in plants of the family Crassulaceae. Historical background Observations relating to CAM were first made by de Saussure in 1804 in his ''Recherches Chimiques sur la Végétatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Butleri
''Isoetes butleri'', commonly known as limestone quillwort, is a species of plant in the quillwort family, a member of the lycophyte The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldes ...s. It is native to the eastern United States, where it is scattered and local. It is found almost exclusively on seasonally wet alkaline soils. Common habitats include rocky prairies and glades, most often over limestone. This species is inconspicuous and easily overlooked, due to its superficial similarity to a vegetative grass or sedge. The leaves of ''Isoetes butleri'' die back at the end of spring, when its habitat becomes hot and dry. It is then reduced to a below ground corm. References {{Taxonbar, from=Q17023023 butleri Flora of the Southeastern United States Flora without expected TNC ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Tegetiformans
''Isoetes tegetiformans'', commonly known as mat-forming quillwort or mat-forming Merlin's grass, is an aquatic lycophyte endemic to the U.S. state of Georgia. It grows exclusively in shallow, temporary pools on granite outcrops, often with only 2 cm of soil. Only 7 populations are known to exist, and three of these have been destroyed since the plant's discovery in 1976. The remaining populations are threatened with habitat destruction Habitat destruction (also termed habitat loss and habitat reduction) is the process by which a natural habitat becomes incapable of supporting its native species. The organisms that previously inhabited the site are displaced or dead, thereby ... due to quarrying, though the species is protected under the U.S. Endangered Species Act. New leaves quickly sprout after fall and winter rains, but during the dry summer months these typically shrivel. References External links Profile at USDA Plants Profile for ''Isoetes tegetiformans'' [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spore
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligule
A ligule (from "strap", variant of ''lingula'', from ''lingua'' "tongue") is a thin outgrowth at the junction of leaf and leafstalk of many grasses (Poaceae) and sedges. A ligule is also a strap-shaped extension of the corolla, such as that of a ray floret in plants in the daisy family Asteraceae. Poaceae and Cyperaceae The ligule is part of the leaf that is found at the junction of the blade and sheath of the leaf. It may take several forms, but it is commonly some form of translucent membrane or a fringe of hairs. The membranous ligule can be very short 1–2 mm ( Kentucky bluegrass, ''Poa pratensis'') to very long 10–20 mm ( Johnson grass, ''Sorghum halepense''), it can also be smooth on the edge or very ragged. Some grasses do not have a ligule, for example barnyardgrass ('' Echinochloa crus-galli''). A ligule can also be defined as a membrane-like tissue or row of delicate hairs typically found in grasses at the junction of the leaf sheath and blade. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homosporous
In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, fungi and protozoa. Bacterial spores are not part of a sexual cycle, but are resistant structures used for survival under unfavourable conditions. Myxozoan spores release amoeboid infectious germs ("amoebulae") into their hosts for parasitic infection, but also reproduce within the hosts through the pairing of two nuclei within the plasmodium, which develops from the amoebula. In plants, spores are usually haploid and unicellular and are produced by meiosis in the sporangium of a diploid sporophyte. Under favourable conditions the spore can develop into a new organism using mitotic division, producing a multicellular gametophyte, which eventually goes on to produce gametes. Two gametes fuse to form a zygote which develops into a ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoetes Histrix
''Isoetes histrix'', the land quillwort, is an aquatic pteridophyte native to the Mediterranean region, northwestern Africa, and the coasts of western Europe northwest to Cornwall. It occurs mainly in temporarily wet habitats, otherwise called vernal pools. The leaves are 3–8 cm long, and summer-deciduous. It differs from ''Isoetes durieui ''Isoetes'', commonly known as the quillworts, is the only extant genus of plants in the family Isoetaceae, which is in the class of lycopods. There are currently 192 recognized species, with a cosmopolitan distribution but with the individual sp ...'' by its large black scales between the leaves, though these are not always present, and a surface of megaspores with tubercles, whereas ''I. durieui'' has a network of ridges. References External linksFlora Europaea: ''Isoetes histrix'' histrix Flora of England Flora of Malta {{Lycophyte-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
