The new leaf of ferns is called:

$A$ fern prothallus is bisexual. If fertilization takes place between the gametes produced by the same prothallus,then it is known as:

$A$: In $Equisetum$,sexual reproduction occurs through sex organs like antheridia and archegonia.
$R$: In pteridophytes,the gametophytic stage is long-lived and responsible for sexual reproduction.

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

Development of embryo in $Selaginella$ is

$Pteridium$ possesses: