Kingdom Plantae: Photosynthetic Eukaryotes

Who created the basis of the modern system of scientific classification?

What percentage of plants are flowering plants?

How many accepted species of plants are there?

What is the name of the plant kingdom in Linnaeus' system?

Where did the ancestors of land plants evolve?

When did the first land plants appear?

What is the estimated height of the tallest Eucalyptus regnans?

What is the primary source of energy for plants?

What is the estimated size of the smallest plants?

What is the pigment responsible for photosynthesis in plants?

What is the term for the study of plants?

Which group of organisms did plants encompass historically, according to Aristotle's biology?

What is the clade that includes green algae and embryophytes or land plants?

What is the estimated number of known plant species?

What is the majority of plant species known to produce?

What is the byproduct of photosynthesis that supports most of Earth's ecosystems?

Kingdom of Photosynthetic Eukaryotes

Plants form the kingdom Plantae, which consists of predominantly photosynthetic eukaryotes.
Plants obtain energy from sunlight using chloroplasts, producing sugars from carbon dioxide and water using chlorophyll.

Exceptions and History

Parasitic plants have lost genes for chlorophyll and photosynthesis, obtaining energy from other plants or fungi.
Historically, the plant kingdom included all living things that were not animals, including algae and fungi.
Current definitions exclude fungi and some algae, and include the clade Viridiplantae (green plants).

Classification and Taxonomy

The clade Viridiplantae includes green algae and embryophytes (land plants).
A definition based on genomes includes Viridiplantae, red algae, and glaucophytes in the clade Archaeplastida.
There are about 380,000 known species of plants, with 260,000 producing seeds.

Importance and Uses

Green plants provide a substantial proportion of the world's molecular oxygen.
Sugars created by plants supply energy for most of Earth's ecosystems and other organisms.
Plants are used for food, building materials, ornaments, writing materials, and medicines.
The scientific study of plants is known as botany.

Taxonomic History and Alternative Concepts

The classification of living things into plants and animals dates back to Aristotle.
Theophrastus and Linnaeus contributed to modern scientific classification, retaining the animal and plant kingdoms.
The term Plantae can refer to one of four concepts, from least to most inclusive.

Evolution and Diversity

There are about 382,000 accepted species of plants, with 283,000 producing seeds.
Flowering plants make up about 85-90% of all plants.
Plants range in scale from single-celled organisms (desmids and picozoa) to the largest trees (megaflora).

Learn about the characteristics of plants, including their ability to produce energy through photosynthesis, using chloroplasts and chlorophyll. Discover the exceptions to this rule and more!