Plant

Plant Definition and Taxonomic History

• Plants are eukaryotes in the kingdom Plantae.
• Historically, plants included algae and fungi.
• Aristotle classified living things into plants and animals based on soul distinctions.
• Linnaeus laid the groundwork for modern scientific classification.
• There are about 382,000 accepted plant species.
• Green plants range from single-celled organisms to towering trees.

Plant Evolutionary History

• Land plants evolved from aquatic ancestors.
• First land plants appeared around 450 million years ago.
• Early plants diversified in the late Silurian period.
• By the end of the Devonian, plants had roots, leaves, and wood.
• Flowering plants evolved rapidly in the Cretaceous period.

Plant Phylogeny

• A 2019 phylogeny based on genomes proposed a comprehensive plant classification.
• Algal groups’ placement is supported by genome-based phylogenies.
• Bryophyta classification is supported by recent genome studies.
• Plant cells have unique features like vacuoles, chloroplasts, and cell walls.
• Land plants arose from chlorophyte and streptophyte algae.

Importance of Plants

• Plants provide oxygen and energy for Earth’s ecosystems.
• There are about 380,000 known plant species.
• Plants are essential for human food, materials, and medicines.
• Botany is the scientific study of plants.
• Plants are vital for sustaining life on Earth.

Parasitic Plants and Evolution

• Some parasitic plants have lost the ability for photosynthesis.
• Current definitions exclude fungi and some algae.

Plant Data Sources