In $Selaginella$,the adaxial outgrowth,from the base of the leaf,is called:

The first group of plants to possess well-developed vascular tissues is ........

Horsetail and fern are

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

Physiological heterospory is seen in

Sporangia are associated with sporophylls. In $P$ plants,sporophylls are distinct,while in $Q$ plants,sporophylls form compact structures called strobili or cones.
$P \quad Q$