Plants: their biology, structure, diversity and human uses

Common types and diversity

Living plants include many familiar forms: trees, herbs, bushes, grasses, vines, ferns and mosses, as well as groups formerly called algae such as the green algae. The scientific study of plants, botany, recognizes hundreds of thousands of living (extant) species. Some organisms that look plant-like — for example fungi and various non‑green algae — are placed in different groups and not treated as plants in modern systems of classification.

Structure and physiology

Typical plants have three main organ systems: stems, roots and leaves. Roots anchor the organism and take up water and mineral nutrients from the soil. The stem provides support and conducts fluids between roots and leaves. Leaves are the principal sites of food production; a leaf contains pores and internal passages that enable gas exchange and water loss.

How plants make food and move water

Plants require sunlight, carbon dioxide, mineral salts and water to synthesize sugars by photosynthesis. The green pigment chlorophyll, concentrated in small organelles called plastids, captures the energy of sunlight. Water absorbed by roots rises through conducting tissues to leaves, and loss of water vapor through leaf pores produces transpiration, a process that helps move fluids and dissolved minerals upward.

Reproduction, life cycles and human interaction

Plants reproduce by a range of methods: spores, vegetative propagation and seeds. Many flowering plants produce seeds that contain an embryo and stored food, allowing new individuals to establish in different places. People who cultivate crops — such as farmers — routinely plant seeds to grow food, fibers and other products. Beyond agriculture, plants are central to ecosystems as primary producers, forming the base of food webs and driving global cycles of carbon and oxygen.

Notable distinctions and uses

Key features that separate plants from other life forms include their typical reliance on photosynthesis, the presence of cell walls containing cellulose in many groups, and a life cycle that often alternates between multicellular stages. Humans use plants for food, medicine, building materials, fuel and ornament, and conserving plant diversity is critical for ecosystem resilience and human well‑being.

• kingdoms
• autotrophic
• eukaryotes
• growth
• trees
• herbs
• bushes
• grasses
• vines
• ferns
• mosses
• green algae
• botany
• extant
• species
• fungi
• non‑green algae
• classified
• stems
• roots
• nutrients
• leaf
• transpiration
• sunlight
• carbon dioxide
• water
• photosynthesis
• chlorophyll
• energy
• plastids
• farmers
• seeds