Plant Classification & Ecology
Chapter 1
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• Ecology
– Study of the interactions between plants, animals
and their environment.
• Habitat
– A habitat is a place where a plant or an animal
lives.
• Biodiversity
– The variety of plants and animals in a habitat
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Interdependence
• Plants and animals depend on each other for:
1. Food
2. Shelter
3. Reproduction
• Insects pollinate flowers
• Animals scatter seeds
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Food chain
Grass
Cow
Human
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Farm Food chain
Grass
Rabbit
Fox
• A food chain is a feeding relationship
between plants and animals through which
energy is transferred.
• Terms
– Producer, Consumer, Herbivore, Carnivore.
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Farm Food Web
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Food Web
• A food web is a number of food chains
connected by the same species
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Plants
• Farmers need to know the names of common
weeds.
• All plants are classified into families.
– All have common characteristics.
• Knowing what family a plant is in, can help to
name a new plant.
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Gramineae (Grass family)
• Includes Grasses, Cereals
– Wheat, Oats, Barley, Maize.
• Are all monocots.
– Have one cotyledon
Yorkshire fog
Maize
Grass = Gramineae
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• Has an inflorescence
– Arrangements of flowers (spiklets) on the stem.
• 3 types
Spiklet
• Spike
• Spiklets not on stalks
• Unbranched
• Barley
• Raceme
• Spiklets on stalks
• Branched
• Wheat
• Panicle
• Spiklets on branched
stalks
• Much branched
• Oats
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Spike, Panicle or Raceme?
Barley
Spike
Hyacinth
Raceme
Perennial Rye Grass
Spike
Oil Seed Rape
Oats
Panicle
Raceme
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Ryegrass
Italian Ryegrass
Perennial Ryegrass
Rye Grass
• Spiklets are alternate
• No stems
• No Awns
• Long Awns
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• Grass can be identified by
–
–
–
–
Flower head (inflorescence).
Ligule.
Spiklet
Colour of infloresence
Blunt Ligule of
Meadow Foxtail
Meadow Foxtail
Pointed, white Ligule of
Cocksfoot
Purple Triangle
shaped flower of
Cocksfoot
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• Members include Perennial Ryegrass,
Cocksfoot, Crested Dogstail, Meadow Foxtail
One sided Inflorescence of Crested
Dogstail
Stem can be seen from one side but
not the other.
Infloresence of Crested Dogstail
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Compositae
• Largest family of plants
• Includes daisies, dandelions, thistles, and
ragwort.
• The family is called Compositae because each
flower is actually composed of many “florets”.
Daisy
Ragwort
Dandelion
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• Daisy
– Has two different types of floret
• White “ray” floret
• Yellow “disc” floret.
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Compositae
• Has a rosette of leaves.
– Leaves arise from same point on stem.
– Arranged around stem.
Dandelion
Thistle
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Cruciferae
•
•
Called Cabbage family
Flowers in the shape of a cross.
– Hence Cruciferae.
•
Floral parts, arranged in fours. (4 sepals, petals &
stamen).
Includes many vegetables
•
–
Cabbage, Brussels Sprouts, Cauliflower, Turnips, Oil
seed Rape.
Charlock
Oil Seed Rape
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Leguminosae (Fabaceae)
•
•
•
•
Called the pea family,
Have 5 petals.
Includes peas, clover, vetch, Gorse
Nitrogen Fixation
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• Has root nodules containing Rhizobium
bacteria.
• Bacteria convert atmospheric Nitrogen, into
nitrate, that can be used by plants.
– Less fertiliser used.
– More productivity.
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To show Clover roots contain Bacteria
• Microbiology experiment
Inoculating Loop
Petri Dish
Mannitol Agar
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1. Wash the roots of a Clover plant.
2. Using a blade cut the root nodules off.
3. Sterilise the outside with disinfectant and
wash again.
4. Crush them in a mortar and pestle with a
small amount of water.
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6. Using a forceps rub the nodule all over the surface
of a dish of Mannitol Agar.
7. Streak the bacteria all over the surface of the agar.
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• Result
– The bacteria will appear on the dish as white
spots.
– Discussion
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To get a pure culture of Rhizobium
bacteria
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Rosacae
• Rose Family.
• Includes apple, pear, peach, plum, cherry,
raspberry, blackberry, and the strawberry.
• Have many carpels and stamens.
• Large flowers
• 5 Petals and many
stamens
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Liliaceae
• Floral parts are in multiples of three.
– 3 sepals, 3 petals, six stamens and three carpels.
• Have fused petals and sepals.
– Not different from each other
– May be joined at end to form tube.
Petals
Tulip Flower
Sepals
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Monocot family
Includes onion, garlic, tulips
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Umbelliferae
Members of this family have flowers shaped
like an upturned umbrella (umbel).
Flowers are small
Contain five sepals, stamens and petals and two
carpels.
Includes parsley, dill, celery, carrots and
parsnips.
Giant hogweeds and cow parsley also belong
to this family.
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Other Families
Ranunculaceae
 Creeping Buttercup.
 Lesser Celandine
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Solanaceae
 Potato family (spud)
 Includes potatoes, tomatoes, and the
“deadly nightshade”.
People thought it represented
sun and its rays
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• Chenopodiaceae
– Goosefoot family
– Includes Sugar Beet
• Has vertical groove
• Produces sugar
• By-products
Fat Hen leaf
– Beet tops
– Beet pulp
– Molasses
– Also includes Fodder beet, Mangolds
Goose Foot
Fodder Beet
• Urticaceae
– Nettle family
– Example Stinging Nettle
– If it stings, it ‘urts
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Polygonaceae
 Rhubarb family – rhubarb, dock.
Broad leaved Dock
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Plantaginaceae
• Plantain family
– Parallel Venation
– Flowers on long spikes
• Ribwort Plantain
Ribwort Plantain
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Video on plant families
https://www.youtube.com/watch?v=yBY44CkQbVc
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To find the population of earthworms
in a field
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To find the population of earthworms
in a field
1. Cut the grass so that it is short.
2. Put a .5 metre quadrat down.
3. Pour water and washing up liquid on the
grass inside the quadrat.
4. Count the number of earthworms that come
to the surface.
5. Multiply by 40 000 to find the number of
earthworms per hectare.
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• HABITAT STUDY
ECOLOGY EXPERIMENTS.
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