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.
What is the sorus composed of?
A sorus consists of a dark mass of powdery teliospores and host tissue.
How are sori arranged?
Sori may be circular or linear. They may be arranged in rows, either parallel or oblique to the costa, or randomly. Their location may be marginal or set away from the margin on the frond lamina. The presence or absence of indusium is also used to identify fern taxa.
What is the function of sorus?
Sorus. Each sorus is a cluster of sporangia. The shape and position of the sori are important for identification of ferns. They provide the main features for identifying the different genera.
What is the function of the indusium?
The sorus is sometimes covered and protected by an indusium, a flap-like tissue arising from the leaf blade. In addition to its protective function for the developing sporangia, indusia may function to control the release of spores.
Do all ferns 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.
What reproductive structures are produced in a sorus?
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.
Who discovered Rhynia and from where?
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 do you mean by sori?
sorus, plural sori, in botany, brownish or yellowish cluster of spore-producing structures (sporangia) usually located on the lower surface of fern leaves. Reproductive structures called sori also occur in various species of marine algae. See also spore.
What is sorus and its types?
A sorus may be protected during development by a scale or flap of tissue called an indusium. In rust and smut fungi, a sorus is a spore mass produced on the leaf of an infected plant. Reproductive structures called sori also occur in various species of marine algae. See also spore. sori.
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.