What is Enation theory?

What is Enation theory?

enation theory The theory that accounts for the origin of the fern leaf by suggesting that it arose from the development of simple outgrowths (enations).

What is Telome explain the Telome theory?

telome theory The theory that the leaves (megaphylls) of ferns and seed plants evolved by the modification of terminal branches (telomes) of stems. It envisages that firstly, instead of the primitive equal (dichotomous) branching of the stem, there developed a main axis with lateral side branches.

What is Enation in plants?

: an outgrowth from the surface of an organ a plant virus causing enations on leaves.

What is Planation in Telome theory?

(c) Planation: The process of planation caused the telomes and mesomes of the truss to shift from a three-dimensional pattern (cruciate dichotomy) to a single plane (fan-shaped dichotomy) (Fig.

What is telome and Mesome?

This theory is based on fossil record and synthesises the major steps in the evolution of vascular plants. A “telome” is defined as ultimate terminal portion of a dichotomising axis 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.

Who discovered Rhynia?

Description. Rhynia gwynne-vaughanii was first described as a new species by Robert Kidston and William H. Lang in 1917. The species is known only from the Rhynie chert in Aberdeenshire, Scotland, where it grew in the vicinity of a silica-rich hot spring.

What is Microphyllous and Megaphyllous?

Microphylls are the leaves with a single vein, which is unbranched. They also do not contain leaf gaps. Generally, microphylls occur in lycophytes and horsetails. In contrast, megaphylls are the other type of leaves with multiple veins and leaf gaps. They occur in angiosperms, gymnosperms, and fronds of ferns.

What is overtopping in Telome theory?

By overtopping, the original dichotomous branching system changed to pseudomonopodial branch with a main stem and lateral branches. Now, the lateral telomes and mesomes of the truss, which were originally 3-dimensional (cruciate) type, became planted (one-dimensional).

What does pea Enation look like?

Leaves develop small yellowish spots that gradually turn white, creating a windowpane appearance. The leaf texture becomes crinkled, with small cracks and blisters evident on leaf undersides. New growth is twisted with small leaves, and stems may turn sideways. Any pods produced are twisted and small.

What is Phyllody disease?

Disease: Phyllody can be a symptom of phytoplasma infection. Phytoplamas are bacteria-like parasites that grow and multiply in the vascular tissue of plants. They are usually spread from plant to plant by plant-sucking insects such as leafhoppers and mites.

What is a Prophyll?

Definition of prophyll : a plant structure resembling a leaf (as a bracteole) or consisting of a modified or rudimentary leaf (as a foliar primordium)

What is the new name of Rhynia major?

Aglaophyton major. The best known plant from the Rhynie chert is Aglaophyton major (FIG. 8.13), a macroplant originally described as Rhynia major, but transferred to a new genus by Edwards based on a reexamination of the original Kidston and Lang slides and the discovery of new specimens (D.S. Edwards, 1986).

Who is the father of paleobotany?

botanist Adolphe-Théodore Brongniart
French botanist Adolphe-Théodore Brongniart is known as the Father of Paleobotany.