An order of the class Lycopsida (clubmosses) that is evolutionarily positioned between two extinct orders. The Lycopodiales are more advanced than the Asteroxylales because their sporangia are unequivocally positioned on the upper surface of modified leaves, but less advanced than the Protolepidodendrales because they lack a uniquely lycopsid feature termed the ligule. All have steles with metaxylem toward the center of the axis, but otherwise show considerable variation. All are perennial nonwoody herbs.