The species that grows on open rocks is known as:

In some of the pteridophytes and gymnosperms,the sporophylls aggregate at the apices of the main stem or its branches to form definite compact structures. These compact structures are called:

The number of functional megaspores in $Selaginella rupestris$ is:

In $Pteridophytes$,meiosis occurs during which of the following processes?

The heterosporous pteridophytes show certain characteristics,which are precursors to the seed habit in gymnosperms. Explain.

Which of the following pteridophytes belongs to the class $Pteropsida$?