The shape of the sporangium in ferns is

What is a fernery?

The basal portion of the ligule of $Selaginella$ is hemispherical and is called:

Selaginella has a character of evolutionary importance. That character is

The stem of $Selaginella$ is anatomically characterized by the presence of

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: