Types of stelar systems and its evolution in pteridophytes and higher plants with. The medicinal uses of some ferns and pteridophytes of india have also been described in some of the recent studies caius, 1935. Types of stelar system and its evolution in pteridophytes plant. This type of vascular system also occurs in conifers with opposite or whorled phyllotaxy. The entire vascular cylinder of the primary axis of pteridophytes is usually referred to as stele. However, the pteridophytes differ from mosses and seed plants in that both generations are independent and freeliving. In this lesson, well discover the characteristics, classification, and life cycle of the group pteridophyta, which includes plant species like ferns and horsetails. Pteridophytes ferns and fern allies the plant list. Pteridophyta general characteristics, classification and. This pdf version does not have an isbn or issn and is not therefore effectively published melbourne code, art. Types of stelar systems and its evolution in pteridophytes and higher plants with ppt.
And among the first of the plants to truly live on land were the pteridophytes. Stelar morphology and the primary vascular system of seed plants. Their leaves are called fronds, which are highly divided except in a few isolated species. In pteridophytes the stele is divided in to different type on the basis of arrangement of xylem and phloem. Endodermis is the boundary between cortex and stele. Stelar theory also says that the cortex and the stele are the two fundamental parts of a shoot system. Pteridophyta characteristics, life cycle, classification. The best of the compendium on medicinal uses of 61 different ferns and fernallies of western ghats has been prepared by benjamin and manickam, 2007. Pdf type of stelar system in pteridophytes farman ali. Pdf stelar morphology and the primary vascular system of seed. The greater part of the stele is composed of vascular tissuesxylem wood and phloem bastwhich are arranged differently in different types of steles. Nov 12, 2014 types of stele in pteridophytes and its evolution. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as cryptogams, meaning that their means of reproduction is hidden.
Modified 17 199 embryophytes bryophytes rhynia fossil lycopodiophyta. A radial dictyostele with two leaftraces and a single roottrace at each leafgap is the most. In a vascular plant, the stele is the central part of the root or stem containing the tissues derived from the procambium. I n pteridophytes the stele is divided in to different type on the basis of arrangement of xylem and phloem. Stelar theory the theory describing the structure of and the interrelationships between various types of steles in higher plants. Pteridophyte definition of pteridophyte by merriamwebster. Types of stele and its evolution in pteridophytes youtube.
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. Stelar evolution of pteridophytes, sporangial organization homospory and heterospory. Pteridophytes introduction, authors and addresses, systematic list, glossary, and key to tribes. Stelar theory article about stelar theory by the free. The stelar morphology of adult andor juvenile plants of 24 species of aspleniaceae was examined.
Outside the stele lies the endodermis, which is the innermost cell layer of the cortex. In 1880, the cryptogams of the plant kingdom were divided. Pdf stelar morphology and the primary vascular system of. Fronds in the largest species of ferns can reach some six metres in length. In pteridophytes, the nature and arrangement of xylem and phloem differ in different groups. Pteridophytes are first group of terrestrial plants which are. It is speculated that life began in the oceans, and through millions of years of evolution, life slowly adapted on to dry land. The modern classification of pteridophytes have been suggested by many scientist according to the sporne1975 pteridophytes have been classified into six classes. Types of stelar system and its evolution in pteridophytes the stele is defined as a central vascular cylinder, with or without pith. Pdf this paper deals primarily with the morphology, anatomy, and. Pdf evolution of stele in plants eranga thilina jayashantha.
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 is any of a division pteridophyta of vascular plants such as a fern that have roots, stems, and leaves but lack flowers or seeds. In higher vascular plants pteridophytes, gymnosperms and angiosperms, the leaf traces are large, and it appears that they play an important role in the vascular system of the axis. Classification of pteridophytes for a long time the division pteridophyta includedthe ferns, lycopods and horsetails.
The sexuality of pteridophytic gametophytes can be classified as follows. Pteridophyte reproduction christian brothers university. Stelar evolution of pteridophytes sporangial organization. The stele is defined as a central vascular cylinder, with or without pith. The pteridophytes are an economically important group of plants. Modern studies of the land plants agree that all pteridophytes share a common ancestor with seed plants. The plant body is differentiated into roots, stem and leaves. Pdf this paper deals primarily with the morphology, anatomy, and evolution of the. Find powerpoint presentations and slides using the power of, find free presentations research about pteridophytes ppt. Primitive siphonostele protostele with central pith. Both these components stele and cortex are separated by the endodermis. Xylem and phloem are the components of vasculature. The ferns are a large group included under pteridophytes. Van tieghem and douliot 1886 interpreted the plant body of vascular plant in the different way.
Difference between pteridophytes and gymnosperms major. This type of stelar organization is the most complex one amongst all vascular cryptogams pteridophytes. Stelar evolution in pteridophytes ppt types of steles and its evolution in pteridophytes ppt what is stele. Pteridophytes or pteridophyta, in the broad interpretation of the term or sensu lato, are vascular plants. They are psilopsida, psilotopsida, lycopsida, sphenopsida, pteropsida and progymnospermopsida. The different species of selaginella are grown as the garden plants. Stelar system, stele, its types and evolution slideshare. Useful notes on the classification of pteridophytes. Types of stelar system in pteridophytes learn more about. Therefore pteridophytes are also called vascular cryptogams. Multiple choice questions on pteridophytes mcq biology. Telome and the evolution of the independent sporophyte among pteridophytes. Slade department of botany, university of otago, dunedin, new zealand received 16 april 1971 summary recently namboodiri and beck 1968c and beck 1970 in proposing a new hypothesis of stelar evolution in the gymnosperms failed to mention its possible application to angiosperms. The structure and development of the stem in pteridophyta and gymnosperms.
According to the older botanists, the vascular bundle is the fundamental unit in the vascular system of pteridophytes and higher plants. Life cycles of lycopodium, selaginella, equisetum, adiantum and marsilea. Pteridophytes or pteridophyta, in the broad interpretation of the term or sensu lato, are vascular plants plants with xylem and phloem that reproduce and disperse via spores. The pteridophytes show heteromorphic alternation of generation. In which of the following group would you place a plant which produces spores, has vascular tissue and lacks seed. In all pteridophytes the dominant plant is the sporophyte brown below with the gametophyte blue below shortlived. Discuss the different types of stele found amoung pteridophytes. As they produce neither flowers nor seeds, they are referred to as cryptogams. On the basis of their anatomy jeffrey in 1902 divided the vascular plants into two types or stocks. These include vascular tissue, in some cases ground tissue and a pericycle, which, if present, defines the outermost boundary of the stele. Ppt evolution projects to try plants planting planets. Now, the lateral telomes and mesomes of the truss, which were originally 3dimensional cruciate type, became planted onedimensional. Write an essay on stelar evolution in pteridophytes with suitable examples and neat diagrams.
Ferns, horsetails often treated as ferns, and lycophytes clubmosses, spikemosses, and quillworts are all pteridophytes. Heterosporous megaspores important in species identifications and gametophyte development is endosporic. Therefore the pericycle xylem and phloem together is called stele. A pteridophyte is a vascular plant with xylem and phloem that disperses spores. Plant science botany evolution bar chart projects to try study learning plants studio. Stelar theory, components of stele, different types of steles in plants, protostele. What are euphylls and how did they most likely evolve. Pteridophytes may represent the closest living relatives sister group to the seed plants.
The printed version, however, was effectively published on 6 june 20. Basic types of steles protostele central xylem, surrounding phloem. For example, the primary vascular system neither fits with current concepts of stelar evolution or with the nodal structure with or without leaf gaps occurring in pteridophytes as summa rized. Types of stelar system and its evolution in pteridophytes. High cholesterol immune system cholesterol lowering foods top remedies benefits of cholesterol supplements. Type of stelar system in pteridophytes all part inside endodermis are called stele. Unlike the ferns, which are a highly successful, flourishing group, the fern allies as. By overtopping, the original dichotomous branching system changed to pseudomonopodial branch with a main stem and lateral branches. The vascular tissues are usually surrounded by pericycle, which. According to the older botanists, the vascular bundle is the fundamental unit in the vascular system of pteridophytes. Similar to the life cycle of seed plants, the pteridophytes also involves the alternation of generations in its life cycle. Pteridophyta general characteristics, classification and stelar system pteridophyta are the most primitive vascular 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. Type of stelar system in pter idophytes all part inside endodermis are called stele.
This fern life cycle is representative of most pteridophytes. Besides xylem and phloem, it includes pith if present and is delimited from the cortex by the pericycle. View and download powerpoint presentations on pteridophytes ppt. Seed plants include the angiosperms, the conifers, and a smaller assortment of other plants. Evolution and biogeography of gymnosperms request pdf. They generally live as an understory plant in shaded, moist areas, although their habitat varies considerably.
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