Pteridophytes were dominant land plants during the carboniferous era and a major source of todays coal and oil. Reproduction in psilotum with diagram pteridophytes. Plants, land plants, embryophytes cutile more or less diploid embryo develops within protective maternal haploid tissue. Merits and demerits of telome theory biology 840 words. Pteridophyta characteristics, life cycle, classification. Zimmermanns telome theory of megaphyll leaf evolution. They also studied the use of pteridophytes as a vegetable and herbal medicine. Concept of icbn b salient features of botanical nomenclature c ranks and nomenclature of taxa d typification e rules of priority f. Sharma 2000 reported the ethnobotanical uses of ferns from rajasthan, india. The sporophyte was the dominant phase of the life cycle of these early pteridophytes. Pteridophytes general characteristics general characters of pteridophytes the vascular cryptogams pteridophytes are plants with feather like leaves. Stout aerial branches bear large conspicuous sporangia fig. Classification of pteridophytes, evolution of vascular systems in plants, stellar system, telome concept, apogamy and apospory, heterospory and seed habits in pteridophytes unit ii 12h early vascular plants. As in seed plants, the greatest diversity of pteridophytes is found in the tropics, with only about six hundred species adapted for life in temperate climates.
Unlike the bryophytes, these plants are in the mainstream of land plant evolution and eventually gave rise to the seed plants. A pteridophyte is a vascular plant with xylem and phloem that disperses spores. Pteridophyte reproduction christian brothers university. These arc standard parts rhat were first observed in fossils. Sumita, assistant professor, department of botany, pggc11, chandigarh. In the classical concept of a microphyll, the leaf vein emerges from the protostele without leaving a leaf gap. The telome concept has been used in understanding the origin and evolution of the following major groups of plants. Reproduction in psilotum with diagram pteridophytes botany.
This page was last modified on 26 december 2014, at 02. Botany pteridophytes class notes for students and teachers of life science biological science. The contents duly unitwise and contents in such manner so that duc importanceis given to requisite laboratov skills. Content is available under the creative commons attribution share. This gametophyte is really small and produced the gametes for the later fertilizaion to build the sporophyte. Most pteridophytes are terrestrial and grow in moist and shady places while some flourish well in open, dry places especially in xeric conditions. The steps leading to the formation of a megaphyll are given in figure 11. Bryophytes are also called amphibians of the plant kingdom because these plants can live in soil but are dependent on water for sexual reproduction. Mar 23, 2018 the pteridophytes are an economically important group of plants. According to telome theory, in a fertile telome truss the usual processes of overtopping, planation and syngenesis resulted in the formation of a web like sporophyll with the sporangia borne at the tips of veins in the margin of the lamina fig. Some pteridophytes are aquatic marselia, azolla and some are epiphytes ophioglossum pendulum.
Some other uses are ferns provide natural vegetation thats important to both wildlife and birds. Some pteridophytes are aquatic and some are epiphytes. The branching of the rhizome and formation of adventitious buds on rhizomes is. This is a portion of the telome theory as proposed by zimmermann 1952 and 1959, who proposed that all of the main plant organs can be derived from simple rhynialike axes called mesomes sterile axes and telomes fertile axes. Silent features of pteridophytes definition, examples. The body of the sporophyte is well differentiated into roots, stem and leaves.
They are psilopsida, psilotopsida, lycopsida, sphenopsida, pteropsida and progymnospermopsida. These ferns, in biological terms, are nothing but the pteridophytes, belonging to the division pteridophyta of the plant kingdom. Pteridophytes or pteridophyta, in the broad interpretation of the term, are vascular plants plants with xylem and phloem that reproduce and disperse via spores. There will be three groups consisting of algae, mycology and phytopathology and microbiology. Seed plants include the angiosperms, the conifers, and a smaller assortment of other plants. Jan 23, 2017 occurence most of the pteridophytes are terrestrial and grow in moist and shady places while some flourish well in open, dry places especially in xeric conditions selaginella lepidophylla. They play an important role in plant succession on bare rockssoil.
Pteridophytes ferns and lycophytes are freesporing vascular plants that have a life cycle with alternating, freeliving gametophyte and sporophyte phases that are independent at maturity. Click here to learn the concepts of silent features of pteridophytes from biology. The printed version, however, was effectively published on 6 june 20. Pteridophytes pteridophytes is a general term for the vascular, free. The entire vascular cylinder of the primary axis of pteridophytes is usually referred to as stele. The phylloids are the prototypes of the microphyllous foliage leaves. Zimmermanns telome theory has been widely accepted for over seventy years as the leading explanation for this evolutionary innovation. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. Pteridophyta teridafata os made from two greek roots that mean winged pteryz. Pteridophyta is the most highly evolved group among the cryptogams. It is speculated that life began in the oceans, and through millions of years of evolution, life slowly adapted on to dry land. In view of the coronavirus pandemic, we are making live classes and video classes completely free to prevent interruption in studies.
Ferns, horsetails often treated as ferns, and lycophytes clubmosses, spikemosses, and quillworts are all pteridophytes. On leafarchitecture as illuminated by a study of the pteridophyta. Pteridophyte definition is any of a division pteridophyta of vascular plants such as a fern that have roots, stems, and leaves but lack flowers or seeds. Pteridophytes general characters and life cycle of ferns email. Many pteridophytes supplement their sexual cycles with various forms of vegetative reproduction. Many pteridophytes supplement their sexual cycles with various forms of vegetative reproduction yatskievych 2003. Rhyniophyta, trimerophytophyta, zosterophylophyta, lepidodendron, lyginopteris. Therefore pteridophytes are no longer considered to form a valid taxon, but the term is still used as an informal way to refer to ferns, horsetails, clubmosses and whisk ferns. Pteridophytes introduction, authors and addresses, systematic list, glossary, and key to tribes. Felix bast is a molecular phylogeneticist, polar explorer, natural historian and a science communicator based in india. Bryophytes were a pivotal step in land plant evolution, and their significance in the regulation of ecosystems and the conservation of biodiversity is becoming increasingly acknowledged.
As they produce neither flowers nor seeds, they are referred to as cryptogams. The plant body of bryophytes is more differentiated than that of algae. General characteristics of pteridophytes key points easy. To apply biological principle and concept to everyday life, especially to matters affecting living things, the environment and economy. Concept of telome theory origin of sporophylls in lycopsida planation of the fertile and sterile telomes reduction of the mesomes and in number of spornagia protolepidodendron and psilotum like axillary sporangia and single veined leaves are evolved. But trust me the first thing that you notice is the abundant foliage of fern plants. The telome theory, largely founded upon paleobotanical evidence, has been accepted as a working hypothesis by many morphologists and paleobotanists concerned with vascular plants other than the angiosperms. This page was last modified on 26 december 2014, at 03. Compound sporangiophores, like those of equisetum, are syntelomes. Range of structure, reproduction and evolution of the gametophytes sex organs. Sporangium development eusporangiate type and leptosporangiate type. The telome theory challenged this morphological trinity by beginning an analysis of. They are the first evolved plant group with vascular tissue system for the conduction of water and food materials.
They usually occur in damp, humid and shaded localities. Alternation of heteromorphic multicellular generations. According to zimmermann, these telomes or telome trusses of primitive rhynia type of vascular plants have been subjected to certain evolutionary processes in varying degrees among the various taxonomic groups. And among the first of the plants to truly live on land were the pteridophytes. Pteridophytes may represent the closest living relatives sister group to the seed plants. A general account of vegetation, morphology, reproductions and evolutionary trends in. Oct 19, 2015 gymnosperms came from the greek root gymnos or naked with spermaor seed. Pdf on apr 18, 2002, paul kenrick and others published the telome theory find, read and cite all the research you need on researchgate.
According to telome theory first proposed by zimmermann 1930, 1938, primitive pteridophytic shoot was naked and dichotomously branched. Classification of pteridophytes as proposed by sporne 1975. Besides having various medicinal properties, the pteridophytes are also employed for a variety of commercial and environmental purposes. Buy isbn9781403930309 at 16% discount by macmillian india ltdnew delhi. Ethnobotanical studies of 40 pteridophytes species by uddin et al. Charan singh university,meerut distribution of marks. The diploid sporophyte plant that produces tiny, microscopic spores and the haploid gametophyte plant that produces eggs and sperms when an egg is fertilized by a sperm, the fertilized egg, now again diploid grows into a new sporophyte plant. The different species of selaginella are grown as the garden plants. According to bierhorst 1971 this theory is too simple and too easily applicable but unfortunately its excessive use has greatly diminished its value. Extant pteridophytes are cosmopolitan but are much better represented in the humid tropics, with only a few families e. Most of the pteridophytes ferns and fernallies show their luxuriant and vigorous growth during the rainy season particularly in the hilly regions usually above 1400 m altitude. The telome theory can be applied to interpret the evolution of a synangium of psilotum. Pteridophytes transition to land megaphylls equisetales.
Despite early success in pteridophytes and gymnosperms, the telome theory never. Pteridophyta is designed to fulfill the needs of undergraduate and postgraduate students of botany. Besides xylem and phloem, it includes pith if present and is delimited from the cortex by the pericycle. Before, they are in the haploid gametophyte stage which is called prothallus for a fern. Pteridophyte definition of pteridophyte by merriamwebster. The telome is the fundamental supercellular building block in plants. International research botany group 2017 international. It envisages that firstly, instead of the primitive equal dichotomous branching of the stem, there developed a main axis with lateral side branches. The first vascular plants rapidly diversified to cover the earth. In other words, gymnosperms are naked seeded plants. This pdf version does not have an isbn or issn and is not therefore effectively published melbourne code, art.
The true story seems to be lost in antiquity and perhaps will never. Various animals use the fronds as food while birds and small creatures use the plants for cover. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as cryptogams, meaning that their means of reproduction is hidden. In plant anatomy and evolution a microphyll or lycophyll is a type of plant leaf with one single, unbranched leaf vein. Pteridophytes are a group of primitive land plants belongs to the cryptogams. Candidates shall be required to answer five questions selecting at least one from each group. The telome theory, largely founded upon paleobotanical evidence, has been accepted as a working hypothesis by many morphologists and paleobotanists concerned with.
The pteridophytes are an economically important group of plants. Leaf gaps are small areas above the node of some leaves where. Although the ovules are naked at the time of pollination, the seeds of gymnosperms are sometimes enclosed by other sporophyte tissues by the time they are mature. Some of the characters of pteridophytes are as follows. Telome and the evolution of the independent sporophyte among pteridophytes. The sporophyte is the conspicuous and familiar plant body. According to telome theory the earliest levees are flattened telomes or phylloids, and the sporangium in all cases, together with its stalk or sporangiophore, is a fertile telome. The telome concept is also involved in a bizarre classification by lam 1948, 194748 of the cormophyta into two large groups, the stachyosporae, in which the sporangia are essentially terminal on fertile telomes, and the phyllosporae, in which.
Pteridophytes biology encyclopedia plant, body, different. To demonstrate sufficient knowledge of the concept of the fossil plants. Study of morphology, anatomy and reproduction of psilopsida, lycopsida and pteropsida. Structural features, geological distribution and evolutionary significance of 3.
The overtopping, reduction and syngenesis have combined to produce a synangium of psilotum fig. He has made several important contributions in the fields of historical linguistics and evolutionary sociopolitics as well. Such an explanation is opposed to the widely accepted concept of. This is a simple concept and explains most of the morphological problems about different organs of a plant. Pteridophytes constitute a significant and important group in the plant kingdom. Telome concept and its significance in the origin of different groups of pteridophytes.
The current trends in the subject are explained in a simple, lucid and understandablewriting style. When you think of forests and woods, you can picture trees, abundant lush green ferns, and other plants. Pteridophytes spend the largest amount of therif lifecycle in the state of the sporophyte. Gymnosperms economical and ecological values albuerolyka.
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