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Vegetative Morphology

All cells of the Thallus arise from an Apical Meristem which has a prominent Apical Cell. All of the cells in the thallus can be traced back to this cell.

The Thallus exhibits branching at the tip which is called Dichotomous. In this case, the branches are equal. This is called Isotomous branching. Iso means Equal.

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Note the Isotomous Branching of these Thalli.



The Apical Cell usually occupies a notch at the apex of the thallus.

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Asexual Reproduction

Thalli fragment naturally, and each fragment can produce another plant, especially if  an apical meristem is present.

Specialized Gemmae may also be formed in cup-like outgrowths.

Gemma Development starts with a single cell which first produces a short filament. This is followed with lateral growth and the production of a small thallus.

The actual propagules are located at the base of the cup & are disk disk-shaped. They have two opposite notches. Each notch has an ___   ____.

When rainwater hits a Gemma Cup some of the Gemmae are ejected.

A  Gemma Ready to Go   ->>

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Steps in Gemma Development


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Lecture Topics