There are hundreds of thousands of plant species on the planet, including trees.
The plant kingdom is a rich and varied world, with species like green algae that grow at a microscopic level and monstrously large and imposing beauties like the giant sequoias. Botanists, who study plant species, have identified more than 300,000 plant species that currently exist. Existing species can be divided into a few groups, including bryophytes, ferns, fern allies, and seed plants.
Mosses, in the Bryophyta division, are small, soft, non-vascular plants.
As with the species of the animal kingdom, the species that currently exist in the realm of the plane represent only a fraction of those that have existed on planet Earth. Archaeologists and geologists regularly discover fossils that attest to the fact that there were plants on this planet that no longer grow anywhere known to humans.
Bryophytes are a group that contains plant species that do not flower and do not produce seeds. These types of plants reproduce through spores. A common type of bryophyte is moss.
Seed plants, also called “spermatophytes”, reproduce by producing seeds. Flowering plants and coniferous trees are examples of this type of plant. Many fruits and vegetables are also part of the seed plant variety.
A coniferous tree is an evergreen tree whose seeds are harvested from the cones the tree produces.
Ferns, like bryophytes, reproduce through spores. What makes this type different from bryophytes is that the plants within it have a vascular structure, meaning they have a xylem and a phloem. There are around 12,000 species within the fern group. The term “ferns” refers to a group of plants that also reproduce through spores and have vascular systems, but are not true ferns.
The first non-vascular plants would have looked like modern lichen.
A brief sketch cannot by any means capture the breadth and variety of the many mosses, ferns, flowers, trees, lichens, shrubs, algae and grasses that currently live on planet Earth. This subject has been of great fascination to scientists of various stripes for thousands of years. One of the best places, beyond the world beyond the front door, to get a sense of the many plant species on the planet is a natural history museum. Another very interesting and beautiful resource of plant information is a book called Das Naturalienkabinet or Cabinet of Natural Curiosities, which is a compilation of the color plates illustrated for commission by a man named Albertus Seba.