Tag Archives: Pteridophyta

Lycopodium: The Creeping Pines

Systematic Position Division: Lycophyta / Lepidophyta Class: Eligulopsida Order: Lycopodiales Family: Lycopodiaceae Genus: Lycopodium Also known as club mosses, Lycopods, creeping pines or tailing pines. Ligule: A membranous outgrowth projecting from the leaf sheath. On the basis of ligule, Lycophyta has 2 classes: Eligulopsida: Lycopodium phylloglossum Liqulopsida – Isoetales, Selaginellales …

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Psilotum: The Whisk Fern

Psilotum commonly known as Whisk-fern. Salient features of Pilotum The sporophytes are dichotomously branched with an underground trhizome and upright branches. The upright branches are leafless. Rhizoids present instead of root. Stem has a relatively simple vascular cylinder. The sporangia are born in groups (trilocular) and form synangioa. Spores produced …

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Stelar Types & Its Evolution in Pteridophytes

Stele is the central cylinder or core of vascular tissue in higher plants and Pteridophytes. It consists of xylem, phloem, pericycle and medullary rays and pith if present. The term stele has been derived from a Greek word meaning rod or column. Van Tieghem and Douliot (1886) introduced this term …

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Classification of Pteridophytes

The term Pteridophyta was first coined by Haeckel. Eichler (1883) divided the plant kingdom into Cryptogamia and Phanerogamia. The Cryptogamia was further divided into Thallophyta. Bryophyta and Pteridophyta. Engler (1909) included the Bryophyta and Pteridophyta under Embryophyta. Due to discovery of the fossil plants, the classification of Pteridophytes has undergone …

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Origin of Pteridophytes

They are the earliest known vascular plants which originated in the Silurian period (400 million years ago) of Palaeozoic Era and subsequently diversified and formed the dominant vegetation on earth during Devonian to Permian period. There are controversies regard­ing their origin and evolution. There are two broad theories about their …

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Telome Theory

A telome is defined as “branch having no leaves but dichotomous branching at either apex or at base or both” i.e., it is the point of the most distal dichotomy to the tip of a branch. The connecting axes between dichotomies are called mesomes. Functionally, telomes are of two types …

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