Some green algae exhibit alternation of generations. All land plants exhibit alternation of generations. No charophytes exhibit alternation of generations. Keeping in mind the recent evidence from molecular systematics, the correct interpretation of these observations is that

The Kingdom Plantae first appeared about 410 million years ago when green algae transitioned from water to land. The differences between land and sea posed a challenge to early colonizing species, which prompted many new adaptations. These adaptations have resulted in the wide variety of plant forms observed today.

There are an estimated 250,000 species, with the greatest diversity in the moist tropics.