What is an indusium in a fern?

What is an indusium in a fern?

A flap of tissue that protects the sori in some ferns. This can take a variety of forms. When spores are mature and ready for release, the indusia usually shrivel or bend backwards to expose the sporangia. Occasionally, if the indusia completely cover the sporangia. they may tear irregularly.

What is the function of the indusium?

In many genera, the sporangia are covered by an indusium. This is a specialized outgrowth of the leaf that functions in protection of the sporangia. This often has the shape of an upside down umbrella and shrivels before the spores are released.

What is indusium where it is found?

These clusters of sporangia are called as sori and are protected by a thin scale or flap of tissue called as indusium during their developmental stage. Sori are found in ferns and lichens, while indusium is characteristic feature of ferns.

Does all fern have indusium?

Sori appear as brown spots and may or may not be present on all leaves. Some species have sori on all the leaves, while others have specialized leaves that bear the sori. When the sporangia dry out, they break open, releasing the spores into the wind.

Is the indusium haploid or diploid?

Is the indusium haploid or diploid? -The indusium is derived from the frond and is therefore diploid.

Where is false indusium found?

by Biology experts to help you in doubts & scoring excellent marks in Class 11 exams. Indusium is found in Fern/Dryopteris/Pteris….Question : Indusium is found in.

Which fern has false indusium?

Description. Members of Pteridaceae have creeping or erect rhizomes. The leaves are almost always compound and have linear sori that are typically on the margins of the leaves and lack a true indusium, typically being protected by a false indusium formed from the reflexed margin of the leaf.

What is false indusium in botany?

In fern: The indusium. One is the so-called false indusium, a rolled-over leaf margin under which sporangia form and mature. The true indusium is a separate and unique formation, the structural origins of which are not clear, that constitutes a more or less papery covering over the sorus.

How old are ferns?

Ferns are ancient plants whose ancestors first appeared on Earth over 300 million years ago. Members of a division of primitive plants called Pteridophytes, ferns are one of the earth’s oldest plant groups and dominated the land before the rise of flowering plants.

What is the umbrella shaped indusium on a fern?

Sori with umbrella-shaped indusia. The indusium is round, shaped like a tiny umbrella and attached to the leaf from the middle. These sword fern indusia do not quite reach the edge of the sori. Individual sporangia are easily visible around the edge of each sorus.

How can you tell if a fern is sterile?

Fern taxa can be distinguished in some cases, by the presence or absence of indusium. Some species of ferns produce a unique frond that is fertile and generates only sori. Such fronds are not photosynthetic and can be easily distinguished from sterile fronds due to their appearance.

What is the difference between sori and indusia ferns?

Sori can vary considerably in shape, arrangement, location and covering depending on the kind of fern. These differences can be useful for identifying ferns. However, depending on the time of year, sori and indusia may not be useful characters because they may be too immature or too mature to be diagnostically useful.

What is sorus in ferns?

Sorus Definition In Botany, Sorus, (sori in plural), is a yellow-brown cluster of structures that produce spores (sporangia). It is found usually on the lower surface of the leaves of ferns. Sorus is sometimes surrounded by a secondary external layer in some varieties of fungi and lichens.