Brown hair found at the base of $Pteris$ leaves are:

Amphicribal or hadrocentric vascular bundles are present in the stem of

$A$: Seeds are formed by some species of spike moss.
$R$: All conditions for seed habit are fulfilled by these species of spike moss.

Horse tails and ferns belong to which group?

Which of the following organisms fell to form coal deposits?

$A$: $Selaginella$ is heterosporous.
$R$: The strobili of $Selaginella$ are unisexual.