Sporangia of which of the following tracheopytes develop singly on the upper side of sporophylls which may or may not be arranged to form strobili_____________?

Explanation

In Lycopsida, sporangia occur singly on the upper surface of sporophylls, and the sporophylls may be arranged into compact cones called strobili. Sphenopsida is a common distractor because it also forms strobili, but its sporangia are borne on specialized sporangiophores rather than ordinary sporophylls.