Kingdom plantae

Introduction

Virtually all other living creatures depend on plants to survive. Through photosynthesis, plants convert energy from sunlight into food stored as carbohydrates. Because animals cannot get energy directly from the sun, they must eat plants (or other animals that have had a vegetarian meal) to survive. Plants also provide the oxygen humans and animals breathe, because plants use carbon dioxide for photosynthesis and release oxygen into the atmosphere.

Plants are found on land, in oceans, and in fresh water. They have been on Earth for millions of years. Plants were on Earth before animals and currently number about 260,000 species. Plants have chlorophyll, a green pigment necessary for photosynthesis. Their cell walls are made sturdy by a material called cellulose and they are fixed in one place (they don’t move).

Mosses or bryophyta are non-vascular. They are an important foundation plant for the forest ecosystem and they help prevent erosion by carpeting the forest floor. All bryophyte species reproduce by spores not seeds, never have flowers, and are found growing on the ground, on rocks, and on other plants.
Originally grouped as a single division or phylum, the 24,000 bryophyte species are now grouped in three divisions: Mosses (Bryophyta), Liverworts (Hepatophyta), and Hornworts (Anthocerotophyta). Also included among the non-vascular plants is Chlorophyta , a kind of fresh-water algae.
Unlike mosses, ferns and related species have a vascular system, but like mosses, they reproduce from spores rather than seeds. The ferns are the most plentiful plant division in this group, with 12,000 species. Other divisions (the fern allies) include Club mosses or Lycopods (Lycopodiophyta) with 1,000 species, Horsetails (Equisetophyta) with 40 species, and Whisk ferns (Psilophyta) with 3 species.

Conifers and allies (Coniferophyta