What are the Plant Groups?
What are Plants?
Most of my pupils are ok with the idea that there are lots of different 'types' of animal - birds, reptiles, fish etc. What they have greater trouble with is the idea that there are also lots of different types of plant. Many will offer suggestions such as flowers, trees and bushes, but this is not a very scientific way of classifying the different types of plant.
I typically start this topic with a simple question:
What is a plant?
Children usually start by saying that plants do not move - this is a misconception. Plants can move, but not from their anchor point. If you watch a sunflower on a time-lapse film it is clear that the plant tracks the sun as it moves across the sky. Plants share the following features:
- They contain chlorophyll and obtain most of their energy from the sun using photosynthesis
- They are multicellular;
- They possess cell walls made of cellulose;
- Undergo alternation of generations;
- Possess apical meristems, which the plants use to grow;
- Can reproduce sexually (although many plants are capable of both sexual and asexual reproduction).
Within these common features, there is plenty of scope for variation. With over 200,000 species of plants on our planet it is vital that these plants are classified to help their study. Why study plants? That's easy! Plants are vital to our survival: they provide us with oxygen and food, as well as medicine, building materials and fuel. Without plants, life as we know it would be impossible.
Plants CAN move - time lapse
The Plant Groups
Vascular Plants; reproduce using spores
Needle-shaped leaves, reproduce using cones and seeds
Vascular Plants; reproduce using flowers
Non-vascular plants; reproduce using spores
Pictures of Mosses
Characteristics of Mosses
Mosses belong to a group of herbaceous plants called bryophytes. Bryophytes also include liverworts and hornworts and are likely the oldest true plant group on Earth. All bryophytes are non-vascular: they lack xylem and phloem, and do not possess true roots.
Mosses are the most familiar of the bryophytes and grow up to 50cm tall at some stages of their life cycle. Like all plants, they are full of chlorophyll which gives them a green colour, although this can be masked by other colours as the moss prepare to release spores.
- Lack roots and can grow in very shallow soil or even bare rock;
- Grow in damp and shady places only;
- Have tiny leaf like structures that are often a single cell thick;
- Lack xylem and phloem (they are non-vascular)
- Reproduce using spores
Pictures of Ferns
Characteristics of Ferns
Ferns represent a shift in power in the plant world. During the first 100 million years of plant evolution, non-vascular bryophytes dominated the globe. Ferns were the first group of seedless vascular plant to evolve; the plant kingdom has never looked back. Ferns developed the xylem, phloem and true root systems typical of all vascular plants.
Ferns are the most widely recognised of the seedless vascular plant group that also includes Lycophytes, whisk ferns and horsetails.
- Possess large leaf like structures called fronds, often divided into leaflets;
- Reproduce using spores (some species produce more than a trillion spores in their lifetime);
- Have fully formed xylem and phloem;
- Possess true roots that anchor the plant in the ground.
This poster summarises the differences between all of the different plant groups. I have one in my classroom!
Pictures of ConifersClick thumbnail to view full-size
Characteristics of Conifers
Conifers mark another paradigm-shift in the plant world - the evolution of pollen and seeds. Conifers were among the first plants to move away from spores and towards seeds. Conifers are known as Gymnosperms ('naked seed') because they do not encapsulate their seeds in ovariers.
Conifers dominate vast forested regions of the Northern Hemisphere, including the Tiger Belt. Here their evergreen* and hardy nature is invaluable in a region where the growing season is short and the winters long and harsh. When spring arrives, conifers have leaves ready to photosynthesise.
- Contain vascular tissue (xylem, phloem, roots);
- Have needle-like leaves;
- Reproduce using male and female cones;
- Produce seeds, not spores.
*Whilst most conifers are evergreen, a few species are deciduous: the dawn redwood, tamarack and larch all lose their leaves each autumn/fall.
Pictures of Flowering Plants
Characteristics of Flowering Plants
90% of all plant species on Earth are flowering plants (angiosperms). They form the staple diet of humanity (cereal crops such as wheat, barley, rice and maize are all flowering plants) and can be pollinated either by the wind, or by drafting in other animals to distribute their pollen (e.g. insects).
All Flowering Plants:
- Possess specialised shoots for reproduction called flowers;
- Encapsulate their seeds in fruits;
- Are vascular plants (possess xylem, phloem and roots).
Flowering Plants can be further subdivided into Monocots and Eudicots.
Plant Group Photos
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Interviews with Plant Groups
Should Children be taught to identify different plants?
Monocots and Eudicots - Characteristics
Veins usually parallel
Veins usually netlike
Vascular Tissue Scattered
Vascular tissue in a ring
Fibrous system (no main root)
Taproot (main root) usually present
Pollen grain with one opening
Pollen grain with three openings
Flower petals in multiples of 3
Flower petals in multiples of 4 or 5