Vascular Plants (Tracheophyta)

Vascular plants, scientifically classified as Tracheophyta, are a large group of plants that possess specialized conducting tissues—internal vessels that transport water, minerals, and nutrients throughout the plant. This group includes trees, shrubs, grasses, herbs, and plants with leaves such as ferns.

What distinguishes vascular plants from non-vascular plants (such as mosses) is the presence of two types of conducting tissue: xylem, which carries water and minerals from the roots to the leaves, and phloem, which distributes sugars produced by photosynthesis to other parts of the plant. This conducting system enabled plants to grow to considerable heights and to inhabit diverse environments.

Structure

Most vascular plants have three main parts: roots, which absorb water and anchor the plant in soil; stems, which support the plant and transport conducting tissue; and leaves, which are the primary site of photosynthesis. The xylem in mature plants contains rigid cells strengthened by lignin, which gives the plant its structural support.

Major groups

Tracheophyta are generally divided into seed plants and plants that reproduce via microscopic spores. Seed plants include gymnosperms (such as conifers) and angiosperms (flowering plants that produce fruits), the latter being by far the most diverse group. Spore-producing plants include ferns and lycophytes.

History and significance

Vascular plants emerged on land during the early Paleozoic era, with the earliest fossils showing small plants lacking well-developed leaves. Today they comprise the bulk of terrestrial ecosystems and the world's vegetation, and form the basis of food supplies for humans, animals, and agricultural economies.