Nonflowering plants

The most ancient land plants on Earth are the nonflowering plants that evolved hundreds of millions of years ago. The earliest were simple plants such as liverworts, mosses, and hornworts, which grow in damp places to avoid drying out. Ferns are more complex but still have to live in moist environments. Instead of producing seeds, almost all nonflowering plants reproduce using tiny spores, which are carried away by wind or water. Only the gymnosperms, a group of nonflowering plants that includes conifers, produce seed-bearing cones instead.

Moss life cycle

A moss’s spore capsule releases spores into the wind. When they land, they grow into leafy shoots with tiny sex organs. When it rains, male sperm cells are able to reach eggs and fertilize them. Each fertilized egg grows a new shoot, and the cycle continues.

Spore capsule

Male Female

1. Scattering spores

2. Sex organs develop Raindrops allow male sperm cells to swim over to the eggs.

Spore-producing shoot

4. Spore capsule grows 3. Fertilization Food factory ❯ The green leaflike part of this moss, called the gametophyte, produces food using energy from sunlight. It does not contain veins to transport water and nutrients, but its surface is so thin that these simply soak through.

Capsule ❯ A spore-producing capsule forms at the tip of each threadlike sporophyte. When the spores are mature, the lid of the capsule breaks off to reveal an opening, through which the spores are released. Every capsule contains hundreds of thousands of tiny spores, which are carried off on the wind.

Brown sporophytes do not make their own food, relying on the green gametophyte instead. Nonflowering plants

Liverwort The first land plants were the tiny liverworts, which appeared around 470 million years ago. Around 9,000 liverwort species exist today.

Moss Mosses grow in fluffy clumps, often in shady areas. Although they may look similar, 12,000 different types of mosses exist around the world.

Hornwort These humidity- loving plants, which are named for their horn-shaped sporophytes, can even grow under water.

Club moss The spore-producing brown spikes of club mosses are held on mosslike stems, but unlike mosses, the green parts are the sporophytes.

Horsetails Horsetails have thin, hairlike leaves that run up their stems like a bottlebrush, and produce spores in conelike structures at the stem tip.

Sporophyte ❯ The sporeproducing, columnlike structure rising from the green body of the moss is a sporophyte. It starts to grow when a female egg cell is fertilized by a male sperm cell.