What is the Classification of Plants?

Why Do We Classify Different Plants?

Living things can be grouped according to their different characteristics. This makes understanding them much easier. We call the method of grouping classification. Each group is called a class.

Classifying living things is called taxonomy and people who carry out classification are called taxonomists.

Plants are complex living things, vital to life on Earth.

We are learning more about plants, how they have evolved, and how they relate to one another every day. While taxonomists used to rely on physical characteristics to classify plants into different groups, scientists today can use other methods to understand how related different plants are to one another.

There are over 320,000 kinds of plants - so that’s a lot of research!

The Diversity of Plants

We can group plants into two major groups: those that produce seeds and those that don’t. Most plants on our planet do produce seeds, which has helped them to thrive.

• Ferns and mosses do not produce seeds.
• Flowering plants and conifers do produce seeds.

There's a wide diversity of plants on Earth that live in different habitats.

Carl Linnaeus

In 1735, a scientist called Carl Linnaeus published a book in which he suggested a process to classify living things. We still use this system today - it’s called the Linnaean system of classification. You can find out more about Linnaeus in this Fifth-Grade Carl Linnaeus Fact File.

The hierarchy of life is organized like a tree. The trunk is the biggest grouping - domain - and you follow the branches all the way to the end of a tiny branch: that’s a species.

Here’s an example of the levels of classification for a prickly wild rose.

Domain - Eukaryote

Kingdom - Plantae

Phylum - Angiosperms

Class - Rosids

Order - Rosales

Family - Rosaceae

Genus - Rosa

Species - Rosa acicularis (prickly wild rose)

What’s in a name?

Linnaeus chose to use Latin for naming living things because by 1735, no-one really spoke Latin. This meant that there was no preferential treatment of any language, and scientists from all over the world can understand each other more easily when referring to the same organism.

In Latin, the different plant groups are:

Non-seed bearing plants

• Pteridophytes - ferns
• Bryophytes - mosses, hornworts and liverworts

Spermatophytes - seed-bearing plants

• Angiosperms - flowering plants
• Gymnosperms - conifers

Plants support life. They keep soil healthy and the ground strong. They provide food, clean air, shelter, and even water.

What Are Facts About Different Plants?

1. Pteridophytesaround the world. These are ferns, plants like spike mosses and horsetails. They have leaves known as fronds. They can be small plants found growing in the forest floor or tall tree ferns with trunks.
2. Over 20,000 named species of Bryophytes live on our planet. They reproduce by releasing spores. They are crucial to ecosystems around the world. For instance, sphagnum moss helps to keep soil healthy, moist, and nourished, allowing for other plants to grow.
3. If you're looking at a plant outside, it's probably an Angiosperm. They are the most diverse group of plants on land: there's over 300,000 known species! From the huge corpse flower to carrots, they have characterized life on earth for over 140 million years.
4. Gymnosperms dominated life on earth before flowering plants took over. You'd have seen lots of gymnosperms like conifers around during the age of the dinosaurs. The biggest trees in the world are gymnosperms like giant sequoia.
5. Seaweed and kelp aren't plants! They are algae. Algae have been included in the classification of plants for centuries. However, algae is very diverse and hard to define. It's neither plant, animal nor fungi - but green algae does share many similarities with green plants.

How can I use Dichotomous Keys to Classify Plants?

Plants - as well as other kingdoms of life - can be classified using a dichotomous key. Take a look at this example.

If you’re looking at a plant, you can observe its characteristics and answer questions in order to find out which species it is. Try out this outdoor classification activity with children to practice this key scientific skill.

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