DIVISION EQUISETOPHYTA PDF

DIVISION EQUISETOPHYTA PDF

– An online study & reference for reserchers, students in botany with full reference on research institutes and scientific. Division Equisetophyta. Stanley L. Welsh. Monte L. Bean Life Science Museum and Department of Botany and Range Science, Brigham Young. Welsh, Stanley L.; Atwood, N. Duane; Goodrich, Sherel; and Higgins, Larry C. ( ) “Division Equisetophyta,” Great Basin Naturalist Memoirs: Vol. 9, Article 7.

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The plants have intercalary meristems in each segment of the stem and rhizome that grow as the plant gets taller.

When ranked as a class, the group has been termed the Equisetopsida [14] or Sphenopsida. This page was last edited on 28 Novemberat Sphenophyllales Archaeocalamitaceae Calamitaceae, A. The Biology and Evolution of fossil plants. The origin of the land flora, a theory based upon the facts of alternation.

The Origin and early diversification of land plants: The Equisetales existed alongside the Sphenophyllalesbut diversified as that group disappeared into extinction, gradually dwindling in diversity to today’s single genus Equisetum. Views Read Edit View history.

The vascular bundles trifurcate at the nodes, with the central branch becoming the vein of a microphyll, and the other two moving left and right to merge with the new branches of their neighbours. They are commonly known as horsetails. The underground parts of the plants consist of jointed rhizomesfrom which roots and aerial eqhisetophyta emerge.

There were three orders of Equisetopsid; the Pseudobornialeswhich first appeared in the late Devonian. Similar spaces, the vallecular canals are formed in the cortex. Retrieved from ” https: In other projects Wikimedia Commons Wikispecies. Plant systematics, a phylogenetic approach.

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Equisetopsida

The extant horsetails are homosporousbut extinct heterosporous species such as Calamostachys casheana appear in the fossil record. Equisegophyta Journal of Botany. In extinct groups, further protection was afforded to the spores by the presence equiisetophyta whorls of bracts – big pointed microphylls protruding from the cone.

Morphology and evolution of vascular plants 3rd ed. These cones comprise spirally arranged sporangiophoreswhich bear sporangia at their edges, and in extant sphenophytes cover the spores externally – like sacs hanging from an umbrella, with its handle embedded in the axis of the cone. The organisms first appear in the fossil record during the late Devonian, [9] a time when land plants were undergoing a rapid diversification, with roots, seeds and leaves having only just evolved.

At the junction “node”, see diagram between each segment is a whorl of leaves. In the only extant genus Equisetumthese are small leaves microphylls with a singular vascular trace, fused into a sheath at each stem node. Charophytes basal Streptofilum Klebsormidiophyceae. International Journal of Plant Sciences.

Evolution of horsetails Equisetales within the major euphyllophyte clade Sphenopsida”. According to that study, the age of the crown group of Equisetum dates at least to the Early Cretaceous, and most probably up to the Jurassic. Morphology of Plants and Fungi 5th ed. Developmental morphology and fuzziness of organ identities”. Glaucocystophyceae Glaucocystis Cyanophora Gloeochaete.

A recent study by Elgorriaga et al. New York and London: Other authors have regarded the same group as a class, either within a division consisting of the vascular plants or, more recently, within an expanded fern group. See also the list of plant orders. Archived from the original PDF on Charophyceae Coleochaetophyceae Zygnematophyceae Mesotaeniaceae.

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Cyanidiophyceae Porphyridiophyceae Compsopogonophyceae Divisiom Rhodellophyceae Bangiophyceae Florideophyceae. The divisioj and evolution of fossil equisetphyta. Equisetopsidaor Sphenopsidais a class of vascular plants with a fossil record going back to the Devonian.

This contrasts with the seed plants, which grow from an apical meristem – i. From Wikipedia, the free encyclopedia.

Equisetopsida – Wikipedia

However, the leaves of Equisetum probably arose by the reduction of megaphyllsas evidenced by early fossil forms such as Sphenophyllumin which the leaves are broad with branching veins. The Sphenophytes comprise photosynthesising, “segmented”, hollow stems, sometimes filled with pith.

Articles with ‘species’ microformats All articles with unsourced statements Articles with unsourced statements from July Commons category link is on Wikidata. All extant species of Equisetum are herbaceous, and have lost the ability to produce secondary growth. Sphenophytes bear cones technically strobilising. By using this site, you agree to the Terms of Use and Privacy Policy. The spores bear characteristic elatersdistinctive spring-like attachments which are hygroscopic: Morphology of vascular plants Lower Groups.