The Bryophytes are the most elementary of the land plants and include the three groups, Anthocerotophyta commonly known as the hornworts, Hepaticophyta (Marchantiophyta) commonly known as the liverworts and Bryophyta commonly known as the mosses. They are distinguished from other plants by their persistent reproductive structures, the gametophytes, the short threads or rhizoids with which they anchor themselves to the ground and the fact that their motile sperm cells must swim to the egg, held in a flask-shaped organ in the gametophyte, through a fluid-filled protective tube of cells.

Also known as Pinophyta, the conifers. Evergreen trees or shrubs, the conifers are the largest of four divisions of the gymnosperms, a term which means 'naked seeds'. The term conifer comes from cone, a cluster of scale-like sporophylls which have pollen sacs on the lower surface.

Group of coned, seed-bearing plants. Cycads are among the oldest of the land plants. They are known to have lived in the Permian, over 200 million years ago (before the age of dinosaurs) and they covered much of the earth in the Mesozoic Era. Today they are found only in tropical and subtropical regions of the world. There are about 250 species in 11 genera. Cycad plants resemble palms or tree-ferns in overall appearance.

Also known as horsetails. The fossil record of the Equisetophyta dates back to the upper Devonian, with a peak in abundance and diversification during the Carboniferous. Today, Equisetum is the sole extant genus, with approximately 15 species, that are divided into two subgenera, Equisetum and Hippochaete. Equisetum has an underground rhizome from which adventitious roots and an upright, photosynthetic stem with whorls of microphylls grow.

The Ginkgophyta are conifer-like seed plants with fan-shaped leaves. They reached their height of diversity and distribution in the Mesozoic Era. The division has one extant species, Ginkgo biloba, a dioecious tree which can live up to 1000 years, which probably originated about 250 million years ago.

The Gnetophyta are a division of the plant kingdom, included among the gymnosperms. Living representatives are found in 3 families in the Class Gnetopsida, Order Gnetales. These three families are Gnetacaea (Gneturns), Welwitschiaceae (Welwitschia), and the Ephedraceae (Mormon-teas). Each family is represented by just one genus. Subcategories for the Gnetophyta are established at the family level for the Ephedraceae and the genus level for the other representatives.

The lycophytes are the oldest extant lineage of vascular plants and contains the club mosses and quillworts. As with the ferns, the gametophytic stage of growth is small and inconspicuous, with the sporophyte being the dominant stage of growth. Extant species are small and herbaceous, however, the fossil records show that many of their ancestors were trees.

The Magnoliophyta is the largest plant group on Earth, containing more than 250,000 described species. The Magnoliophyta is subdivided into two classes, Liliopsida (monocots) and Magnoliopsida (dicots). Plants in this division are also termed the Angiosperms, or flowering plants. They have leaves, stems, roots, and vascular tissue (xylem and phloem). The ovules develop into seeds and are enclosed within an ovary, thus the term angiosperm, meaning "enclosed seed". The flowering plants include all cereal grains, grasses, broad-leaved shrubs and trees and most ornamentals.

Ferns are the biggest and most diverse group of non-flowering plants, with about 11,000 species. Most species live in the tropics and many are epiphytes on trees. They typically have large feathery leaves or fronds which are tightly coiled when young, unwinding as they expand. Some ferns are large enough to be called tree ferns but they do not develop a trunk structure, the stalks of the fronds sprouting directly from a rhizomous rootstock. The reproduction of ferns is complex. Spores are produced on the undersides of the fronds. If these fall in a suitable damp place they develop into small heart-shaped structures called prothalli. After a further sexual stage, a new plant grows from a female prothallus.

Also called the whisk ferns, these are the simplest of the vascular plants. The division of consists of two genera, Psilotum and Tmesipteris. As with angiosperms, plants of the Psilotophyta have vascular tissue (xylem and phloem), however, they are characterised by the lack of roots, and sometimes the lack of leaves. The plants consist of a small, underground, gametophyte, which lacks chlorophyll and has associations with mycorrhizal fungi. The have a life cycle similar to that of ferns, with motile sperm and a self-sustaining, photosynthetic sporophyte.

For sites about both ferns (Polypodiophyta) and their allies: horsetails (Equisetophyta), club mosses (Lycopodiophyta), and whisk-ferns (Psilotophyta).