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Ophioglossophyta
Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the subclass Ophioglossidae. The Ophioglossidae are one of the groups traditionally known as eusporangiate ferns. Members of the family differ from other ferns in a number of ways. Many have only a single fleshy leaf at a time. Their gametophytes are subterranean and rely on fungi for energy. Description Members of Ophioglossaceae are usually terrestrial (excepting a few epiphytic species of '' Ophioglossum'') and occur in both temperate and tropical areas. They differ from the other ferns in several respects: * Many species only send up one frond or leaf-blade per year, producing only a single leaf at a time. The leaves are usually fleshy, and in temperate areas will often turn brownish or reddish during colder months. * Instead o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophioglossum Vulgatum
''Ophioglossum vulgatum'', commonly known as adder's-tongue, southern adders-tongue or adders-tongue fern, is a species of fern in the family ''Ophioglossaceae''. The adder’s tongue fern is generally believed to have the largest number of chromosomes wit1262 compared to the human’s 46. Distribution It is native to many regions with a wide scattered distribution: throughout temperate through tropical Africa and throughout the temperate Northern Hemisphere in Europe, northeastern North America, temperate Asia, and Eurasia. This small, hard-to-spot plant can occur singly in unimproved pastures, rock crevices and grassy path-sides, but also can occur in colonies of hundreds of plants in sand dunes. Description ''Ophioglossum vulgatum'' grows from a rhizome base to 10–20 cm tall (rarely to 30 cm). It consists of a two-part frond, separated into a rounded diamond-shaped sheath and narrow spore-bearing spike. The spike has around 10-40 segments on each side. It repro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporophyll
A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or microsporangia and are called microsporophylls. The overlap of the prefixes and roots makes these terms a particularly confusing subset of botanical nomenclature. Sporophylls vary greatly in appearance and structure, and may or may not look similar to sterile leaves. Plants that produce sporophylls include: ''Alaria esculenta'', a brown alga which shows sporophylls attached near the base of the alga.Dickson, Carola I. 1963. ''British Seaweeds''. The Kew Series. Lycophytes, where sporophylls may be aggregated into strobili (''Selaginella'' and some ''Lycopodium'' and related genera) or distributed singly among sterile leaves (''Huperzia''). Sporangia are borne in the axil or on the adaxial surface of the sporophyll. In heterosporous members ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grape Fern
''Sceptridium'' is a genus of seedless vascular plants in the family Ophioglossaceae, closely allied to (and often included as a subgenus of) the genus '' Botrychium'' (the moonworts and grapeferns). It is also closely related to the genus '' Botrypus'' (the rattlesnake fern, often treated as the subgenus ''Osmundopteris'' under ''Botrychium''). ''Sceptridium'' species are commonly called the grape-ferns. These plants are small with fleshy roots, and reproduce by spores shed into the air. They differ from the moonworts in having at least some sterile fronds (all fronds in ''Botrychium'' are spore-bearing), and in the fronds being bi- or tri-pinnate (''Botrychium'' are single pinnate, or rarely bipinnate); and from ''Botrypus'' in being evergreen, or at least winter-green (''Botrypus'' are deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moonwort
''Botrychium'' is a genus of ferns, seedless vascular plants in the family Ophioglossaceae. ''Botrychium'' species are known as moonworts. They are small, with fleshy roots, and reproduce by spores shed into the air. One part of the leaf, the trophophore, is sterile and fernlike; the other, the sporophore, is fertile and carries the clusters of sporangia or spore cases. Some species only occasionally emerge above ground and gain most of their nourishment from an association with mycorrhizal fungi. The circumscription of ''Botrychium'' is disputed between different authors; some botanists include the genera '' Botrypus'' and '' Sceptridium'' within ''Botrychium'', while others treat them as distinct. The latter treatment is provisionally followed here. Taxonomy * – pointed moonwort * – Alaska moonwort * – upswept moonwort, triangle-lobed moonwort, upward-lobed moonwort * – northern moonwort * – prairie moonwort, prairie dunewort, Iowa moonwort * – dainty moo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophioglossum Malviae
''Ophioglossum malviae'' is a species of fern in the genus ''Ophioglossum ''Ophioglossum'', the adder's-tongue ferns, is a genus of about 50 species of ferns A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neit ...'' and found in the forests of Ahwa in the Dang District of Gujarat. It is claimed to be the world's smallest land fern, with the entire plant growing to a size of about only 1 to 1.5 cm. References Ophioglossaceae {{fern-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diploid
Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively, in each homologous chromosome pair, which chromosomes naturally exist as. Somatic cells, tissues, and individual organisms can be described according to the number of sets of chromosomes present (the "ploidy level"): monoploid (1 set), diploid (2 sets), triploid (3 sets), tetraploid (4 sets), pentaploid (5 sets), hexaploid (6 sets), heptaploid or septaploid (7 sets), etc. The generic term polyploid is often used to describe cells with three or more chromosome sets. Virtually all sexually reproducing organisms are made up of somatic cells that are diploid or greater, but ploidy level may vary widely between different organisms, between different tissues within the same organism, and at different stages in an organism's life cycle. Half ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophioglossum Reticulatum
''Ophioglossum reticulatum'', the netted adder's-tongue, is a species of fern in the family Ophioglossaceae. It has a pantropical/pansubtropical distribution; Latin America, the Caribbean, Sub-Saharan Africa, Madagascar, Yemen, the Indian Subcontinent, Southeast Asia, warmer parts of China, Malesia, Korea, Japan, and many tropical islands. A hexaploid Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains ..., it has the highest number of chromosomes of any plant, 720. Its leaves—or leaf, individuals only grow one per year—are edible, and are regularly consumed by people in Africa and Asia. References reticulatum Ferns of the Americas Ferns of Africa Ferns of Asia Ferns of Oceania Flora of Mexico Flora of Central America Flora of the Caribbean Flora of South America Flora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Organisms By Chromosome Count
The list of organisms by chromosome count describes ploidy or numbers of chromosomes in the cell (biology), cells of various plants, animals, protists, and other living organisms. This number, along with the visual appearance of the chromosome, is known as the karyotype, and can be found by looking at the chromosomes through a microscope. Attention is paid to their length, the position of the centromeres, banding pattern, any differences between the sex chromosomes, and any other physical characteristics. The preparation and study of karyotypes is part of cytogenetics. File:Human karyotype with bands and sub-bands.png, Karyotype of a human being. It shows 22 Homologous chromosome, homologous autosomal chromosome pairs, both the female (XX) and male (XY) versions of the two sex chromosomes, as well as the human mitochondrial genetics, mitochondrial genome (at bottom left). File:Chromosome2 merge.png, Fusion of ancestral chromosomes left distinctive remnants of telomeres, and a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root
In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the surface of the soil, but roots can also be aerial or aerating, that is, growing up above the ground or especially above water. Function The major functions of roots are absorption of water, plant nutrition and anchoring of the plant body to the ground. Anatomy Root morphology is divided into four zones: the root cap, the apical meristem, the elongation zone, and the hair. The root cap of new roots helps the root penetrate the soil. These root caps are sloughed off as the root goes deeper creating a slimy surface that provides lubrication. The apical meristem behind the root cap produces new root cells that elongate. Then, root hairs form that absorb water and mineral nutrients from the soil. The first root in seed producing plants is the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Annulus (botany)
{{Short description, A ring of specialized cells on the sporangium An annulus in botany is an arc or a ring of specialized cells on the sporangium. These cells are arranged in a single row, and are associated with the release or dispersal of spores. Ferns In leptosporangiate ferns, the annulus located on the outer rim of the sporangium and serves in spore dispersal. It consists typically of a ring or belt of dead water-filled cells with differentially thickened cell walls that stretches about two-thirds around each sporangium in leptosporangiate ferns. The thinner walls on the outside allow water to evaporate quickly under dry conditions. This dehiscence causes the cells to shrink and a contraction and straightening of the annulus ring, eventually rupturing the sporangial wall by ripping apart thin-walled lip cells on the opposite side of the sporangium. As more water evaporates, air bubbles form in the cells causing the contracted annulus to snap forward again, thus dislodging an ... [...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 new s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporophyte
A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote produced when a haploid egg cell is fertilized by a haploid sperm and each sporophyte cell therefore has a double set of chromosomes, one set from each parent. All land plants, and most multicellular algae, have life cycles in which a multicellular diploid sporophyte phase alternates with a multicellular haploid gametophyte phase. In the seed plants, the largest groups of which are the gymnosperms and flowering plants (angiosperms), the sporophyte phase is more prominent than the gametophyte, and is the familiar green plant with its roots, stem, leaves and cones or flowers. In flowering plants the gametophytes are very reduced in size, and are represented by the germinated pollen and the embryo sac. The sporophyte produces spores (hence t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
