Pteridophytes or ferns first appeared in the fossil record more than 350 million years ago. They generally live as an understory plant in shaded, moist areas, although their habitat varies considerably. Pteridophyta characteristics, life cycle, classification. Some other uses are ferns provide natural vegetation thats important to both wildlife and birds. Molecular evolution of pteridophytes and their relationship to seed plants. Besides having various medicinal properties, the pteridophytes are also employed for a variety of commercial and environmental purposes. Pteridophytes may represent the closest living relatives sister group to the seed plants. Online course stellar structure and evolution this course is taught as a halfmodule for phy412 astrophysics in the department of physics and astronomy at queens.
According to this theory, the pith is formed as a result of the invasion of cortical parenchymatous cells into the stele. Firstly all the botanists divided the plant kingdom into two large groups cryptogamia and phanerogamia, linnaeus 1754 used the term cryptogams for the first time for those plants which did not possess visible sex organs. Lloyd in flowering plants many of the diverse characteristics utilized in systematics to determine phylogenetic relationships represent direct adaptations to specific methods of pollination or reproduction. Were pteridophytes always less abundant than phanerogamic plants. The sporophyte was the dominant phase of the life cycle of these early pteridophytes. Primitive siphonostele protostele with central pith.
Read the introductory remarks and list of characteristics of the bryophytes p. Pteridophytes pteridophtyes are a phylum of plants. Many aspects of difficult interpretation exist in the phylogenetic history of land plants. The pteridophytes ferns and fern allies pteridophytes are vascular plants and have leaves known as fronds, roots and sometimes true stems, and tree ferns have full trunks.
They are the vascular plants those having xylem and phloem tissues that reproduce by releasing spores rather than seeds, and they include the highly diverse true ferns and other graceful, primarily forestdwelling plants. A newer method in which resins and polymers are directly injected into xylem tissue has proven. Ferns belong to a group of plants called featherplants or pteridophytes, along with club mosses and horsetails. The pteridophytes occupy the intermediate position in between the bryophytes on one hand and the phanerogams on the other. Pteridophyta teridafata os made from two greek roots that mean winged pteryz. These keywords were added by machine and not by the authors. The lower cryptogams algae, fungi and bryophytes have no conducting system. This process is experimental and the keywords may be updated as the learning algorithm improves.
The structure and function of xylem in seed free vascular plants. Reproductive biology and evolution in the pteridophyta. It is speculated that life began in the oceans, and through millions of years of evolution, life slowly adapted on to dry land. According to him, the primitive type of stele is protostele. Pteridophytes fern and fern allies comprise more than 10,000 species throughout the world and are roughly distributed among 305 genera. Pteridophytes are a vascular plant and since bryophytes have no vascular system they are not capable to transport the water and nutrients from one part of the plant to another but pteridophytes can. Pteridophytes biology encyclopedia plant, body, different. Summary and conclusions 83 chapter5 summary and conclusions pteridophytes are one of the most ancient plants. Summary and conclusions pteridophytes are one of the most ancient plants. Morphological diversity and evolution of vegetative organs pteridophytes download pteridophytes or read online here in pdf or epub.
Pteridophytes do not have seeds or flowers either, instead they also reproduce via spores. The invasion of pith occurs through the leaf gap or branch gap. Ferns, horsetails often treated as ferns, and lycophytes clubmosses, spikemosses, and quillworts are all pteridophytes. Medicinal potential of pteridophytesan antihyperglycemic and antinociceptive activity evaluation of methanolic extract of whole plants of christella dentata. Pteridophytes or pteridophyta, in the broad interpretation of the term, are vascular plants plants with xylem and phloem that reproduce and disperse via spores. Why are pteridophytes better adapted to dry land than bryophytes. A pteridophyte is a vascular plant with xylem and phloem that disperses spores. Coal is made largely of fossilized featherplants of the. Each of these can be divided into life forms according to a series of morphological and other characters. Although bryophytes and pteridophytes have gametes tha depend on water for fertilization, the emergence of conducting vessels in this last group facilitated life in a terrestrial environment. In some pteridophytes the sporangia develop on stems i. Pteridophytes constitute a significant and important group in the plant kingdom. The following separation of the main growth forms of pteridophyta is proposed.
Furthermore, in hymenophyllous ferns, the sporophyte is. There are also some purely aquatic ferns such as water fern or water velvet salvinia molesta and mosquito ferns azolla species. Phytochemical studies in pteridophytes growing in brazil. This was around the time when coal was being formed.
A concept based exclusive material pteridophytes, gymnosperms. Various animals use the fronds as food while birds and small creatures use the plants for cover. Unlike the bryophytes, these plants are in the mainstream of land plant evolution and eventually gave rise to the seed. The molecular data indicate that lycopsids are monophyletic and are the earliest diverging group within the vascular land. Ferns can be used to illustrate the life cycle stages common to all pteridophytes. It is speculated that life began in the oceans, and through millions of years of evolution, life slowly. Basic types of steles protostele central xylem, surrounding phloem. 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. Pteridophyte definition of pteridophyte by the free. Jeffrey 1898, for the first time pointed out the stelar theory from the point of view of the phylogeny. All pteridophytes have a true alternation of generations, in which a dominant sporophyte generation produces spores through meiosis, and a freeliving gametophyte generation forms gametes egg and sperm by mitosis. Heterosporous megaspores important in species identifications and gametophyte development is endosporic. The different species of selaginella are grown as the garden plants.
Characteristics of pteridophytes, morphology of pteridophytes, reproduction of pteridophytes, homosporous and heterosporous pteridophytes, megaspore and microspores, gametophytes of pteridophytes, fertilization, zygote and embryo of pteridophytes, life cycle. Sumita, assistant professor, department of botany, pggc11, chandigarh. The modern classification of pteridophytes have been suggested by many scientist according to the sporne1975 pteridophytes have been classified into six classes. On the basis of ontogenetical studies, stomata in the pteridophytes may be broadly classified into. Pteridophyta the word cryptogams means that the plant produce by spore and do not produce by seed. Stomatal patterns in pteridophytes an evolutionary approach. What is one evolutionary advantage pteridophytes have over. A few pteridophytes are aquatic while still others are. Phytochemical studies in brazilian pteridophytes soeder 1985 reported a large inventory of papers that appeared between 1966 and 1984 on the chemical constituents of pteridophytes.
Life cycles of lycopodium, selaginella, equisetum, adiantum and marsilea. Stelar evolution in pteridophytes ppt types of steles and its evolution in pteridophytes ppt what is stele. Jan 23, 2017 reproduction the sporophytes reproduce by spores which are produced within sporangia. They possess certain combinations of major characters which are not found in bryophytes or in phanerogams. Occurrence and evolution of pteridophytes biology boom. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as cryptogams, meaning that their means of reproduction is hidden. It is a 4th year msci course, which is compulsory for students on the physics with astrophysics pathway and optional for other physics and physics and applied mathematics students. As they produce neither flowers nor seeds, they are referred to as cryptogams.
They had acquired certain characteristic features in the early geologic period that helped them to make their successful adaptation on land. Pteridophytes article about pteridophytes by the free. Pteridophytes general characters ppt general characteristics, life cycle and reproduction of pteridophytes ppt what are pteridophytes. The molecular data indicate that lycopsids are monophyletic and are the earliest diverging group within the vascular land plants. Their leaves are called fronds, which are highly divided except in a few isolated species. These are nonflowering, vascular and sporebearing plants, which include ferns and fernallies. Systematic revision of pteris and ecology of ferns in. Most pteridophytes are terrestrial plants and thrive well in abundant moisture and shade while some flourish well in open, dry situations especially in xeric conditions. Occurrence and evolution of pteridophytes with its origin and economic importance in pteridophyta is a group of ancient plants.
A few pteridophytes are aquatic while still others are epiphytes. Already on the origin of plant lineage, we still have no safe dating for the endosymbiotic event, i. Stelar theory, components of stele, different types of steles in plants, protostele. Complete 18s ribosomal rna sequence data from representatives of all extant pteridophyte lineages together with rna sequences from different seed plants were used to infer a molecular phylogeny of vascular plants that included all major land plant lineages. In addition, in pteridophytes, the gametophyte is often very thin and can be unistratose, especially at the margins yatskievych, 2003. The origin and early evolution of plants on land pdf. Extant pteridophytes are cosmopolitan but are much better represented in the humid tropics, with only a few families e. This author lists a total of 671 references, but only one work had been carried out in brazil miraglia et al. Among green plant lineages, none are as speciesrich as vascular plants tracheophytes. They formed the dominant part of the earths during palaeozoic and mesozoic periods on soral evolution. Filicales, introductions to both fossil and recent plant taxa, links.
The first vascular plants rapidly diversified to cover the earth. With the commencement of monsoon about mid june, the ferns and fernallies start growing vigourously and luxuriantly. Stelar evolution of pteridophytes, sporangial organization homospory and heterospory. 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. Pteridophytes ferns and fern allies the plant list. A read is counted each time someone views a publication summary such as the title, abstract, and list of authors, clicks on a figure, or views or downloads the fulltext. This pdf version does not have an isbn or issn and is not therefore effectively. The pteridophytes are vascular cryptogams because they have well developed conducting system. Unlike the bryophytes, these plants are in the mainstream of land plant evolution and eventually gave rise to the seed plants. The pteridophytes are the successful colonisers on land habit. Sporophylls the leaves that bear sporangia are known as sporophylls. Pteridophytes were dominant land plants during the carboniferous era and a major source of todays coal and oil. The algae fungi bryophytes and pteridophytes are all cryptogams.
Pteridophyta is the most highly evolved group among the cryptogams. In protostele, the vascular tissue is a solid mass and the central core of the xylem is completely surrounded by the strand of phloem. The most characteristic feature of the pteridophytes is the presence. Haeckel 1866 called these groups of plants as pteridophytes because of their pinnate or feather like fronds leaves. Seed plants include the angiosperms, the conifers, and a smaller assortment of other plants. Characteristics of pteridophytes, morphology of pteridophytes, reproduction of pteridophytes, homosporous and heterosporous pteridophytes, megaspore and microspores, gametophytes of pteridophytes, fertilization, zygote and embryo of. All books are in clear copy here, and all files are secure so dont worry about it. Stelar evolution of pteridophytes sporangial organization. They are psilopsida, psilotopsida, lycopsida, sphenopsida, pteropsida and progymnospermopsida. The pteridophytes are an economically important group of plants.
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