Definition and Taxonomic history

  • Plants are eukaryotes that form the kingdom Plantae.
  • They are predominantly photosynthetic organisms and use chloroplasts to produce sugars.
  • Some plants are parasitic.
  • The plant kingdom historically included algae and fungi, but current definitions exclude them.
  • Aristotle classified living things into plants and animals based on their souls.
  • Theophrastus continued Aristotle's work in plant taxonomy.
  • Linnaeus created the modern system of scientific classification and named the plant kingdom Vegetabilia.
  • There are about 382,000 accepted species of plants, with the majority producing seeds.
  • Different green plant divisions have varying species count estimates.

Evolutionary history

  • Land plants evolved from ancestors in water.
  • The first land plants appeared around 450 million years ago.
  • Complex plants may have developed over 1000 million years ago.
  • Bryophytes, club mosses, and ferns appeared in the fossil record.
  • Basic features of plants today, such as roots and leaves, were present by the end of the Devonian period.


  • A 2019 phylogeny based on genomes and transcriptomes proposed the relationship between plant species.
  • Algal groups are supported by phylogenies based on genome sequencing.
  • Chlorophyte algae and streptophyte algae are treated as paraphyletic in the analysis.
  • The phylogeny includes the clade Viridiplantae, which consists of green algae and land plants.
  • The clade Archaeplastida includes Viridiplantae, red algae, and glaucophytes.

Importance and uses

  • Plants provide a substantial proportion of the world's molecular oxygen.
  • They create sugars that supply energy for Earth's ecosystems.
  • Humans use plants for food, building materials, ornaments, writing materials, and medicines.
  • Grain, fruit, and vegetables have been domesticated for millennia.
  • The scientific study of plants is known as botany.


  • Plants can be parasitic and obtain energy from other plants or fungi.
  • Plants historically included algae and fungi, but current definitions exclude them.

Plant Mentions

Plant Data Sources

Reference URL
Knowledge Graph