R2101 - Plant classification

Question 1

1.1 What is a conifer?

Answer 1

• Mostly evergreen
• Perennial woody plants with secondary growth
• Cones and naked seeds
• Needle-shaped or scalelike leaves

Question 2

1.1 Name 2 examples of a conifers

Answer 2

Pinus spp. (Pines)
Cupressus spp. (Cypresses)

Question 3

1.1 What are the characteristics of a flowering plant?

Answer 3

• Evergreen and deciduous
• Herbaceous and woody
• Flowers and enclosed seeds
• All life cycles.

Question 4

1.1 Describe a Monocotyledon or Monocot.

Answer 4

Seed - has one cotyledon (part of the embryo within seeds that form the first leaves when the plant germinates)

Roots - Fibrous roots ( thin, moderately branching roots growing from the stem)

Stem - Vascular bundles carrying water and nutrients up and down the stems are scattered randomly

Leaves - Long narrow leaves with parallel veins

Flowers - Floral parts in multiples of 3

Question 5

1.1 Describe a Dicotyledon or Dicot.

Answer 5

Seed - has two cotyledons (part of the embryo within seeds that form the first leaves when the plant germinates)

Root - tap roots ( a long straight tapering root growing vertically downwards and forming the centre from which subsidiary rootlets grow)

Stem - the vascular bundles that carry water and nutrients up and down the stems are arranged in a neat ring

Leaves - broad leaves with veins forming a network

Flowers - floral parts in multiples of 4 or 5

Question 6

1.2 Why are botanical plant names important?

Answer 6

• Stability over time
• Common names are different from place to place, change over time and are often ambiguous
• Uniqueness to a species
• Internationally understood, allowing plant identification and communication

Question 7

1.2 What does genus (genera plural) mean?

Answer 7

• A group of individuals within a family which have characteristics in common

Question 8

1.2 What does species mean?

Answer 8

• Basic unit of classification
• Group of individuals with the greatest mutual resemblance
• Abilty to breed amongst each other

Question 9

1.2 Describe the binomial system of naming plants.

Answer 9

• Binomial means two names.
• First part GENUS (plural genera)
• Second part specific name, and refers to the SPECIES
• There may be one species in a genus or hundreds

Question 10

1.2 How are binomial names written?

Answer 10

Using an italic script, with the Genus name given a capital letter, the specific name is NEVER given a capital letter.

Question 11

1.2 Give 3 examples of binomial names.

Answer 11

• Myosotis sylvatica
• Cyclamen coum
• Fatsia japonica

Question 12

1.2 What is a cultivar?

Answer 12

A selection made from a species and propagated vegetatively (not by seed) so that every individual is identical.

Question 13

1.2 How are cultivars written?

Answer 13

Cultivar names come after the Genus and species and are enclosed within ‘inverted commas’ and written in regular script.

Question 14

1.2 Give 3 examples of cultivar names.

Answer 14

• Nigella damascena ‘Miss Jekyll’
• Cosmos bipinnatus ‘Rubenza’
• Hedera helix ‘White Ripple’

Question 15

1.3 What are the 5 stages in the life cycle of a plant?

Answer 15

• seed
• juvenile
• adult
• senescence
• death

Question 16

1.3 Describe the seed stage.

Answer 16

• Germination occurs at correct temperature, when enough water and oxygen are present (some seeds also require light)
• a root grows downwards to access water
• shoots grow upwards above ground to harvest energy from the sun
• leaves form

Question 17

1.3 Describe the juvenile stage.

Answer 17

• plant increases in size as cells enlarge and differentiate to form roots, stems and leaves
• in some plants leaves are larger and different in shape to the adult plant
• non-reproductive stage; no flowers, fruit or seeds

Question 18

1.3 Describe the adult stage.

Answer 18

Reproductive phase where the plant produces flowers, fruit and seeds.

Question 19

1.3 Describe the senescence stage.

Answer 19

• follows maturity as plant growth deteriorates
• herbaceous perennial occurs in above ground growth
• annuals the entire plant

Question 20

1.3 Describe the death stage.

Answer 20

• annual’s life cycle is over in one season ending in death
• perennial’s roots survive through winter

Question 21

1.3 Name some reasons why life cycles of plants are significant to horticulture.

Answer 21

• Understanding what to plant and when; so the desired growth is reached at the preferred time
• When lifecycles are understood they can be manipulated to produce new plants at a desired stage. E.g. juvenile round leaved growth of eucalyptus is desirable to the floristry industry so it’s coppiced to produce a continual output of juvenile growth
• Fundamental for planning planting schemes
• Cost effective - planting from seeds is much cheaper than mature plants

Question 22

1.4 Define the botanical term annual with 2 examples.

Answer 22

A plant that completes its life cycle in one growing season

• Limnanthes douglasii
• Nigella damascena‘Miss Jekyll’
• Cosmos bipinnatus‘Rubenza’

Question 23

1.4 Define the horticultural term annual with 2 examples.

Answer 23

In the horticultural world many naturally perennial plants may be grown as annuals and replaced after their first season of growth.

Pelargonium zonale Rudbeckia hirta ‘Cherry Brandy’

Question 24

1.4 Define botanical the term biennial with two examples.

Answer 24

A plant with a life cycle that spans two growing seasons.

• Angelica* sylvestris
• Digitalis* purpurea

Question 25

1.4 Define the horticultural term biennial with two examples.

Answer 25

In the horticultural world many naturally perennial plants may be grown as biennials and replaced after their second season of growth.

• Alcea rosea (Hollyhock)
• Erysimum cheiri (Wallflower)

Question 26

1.4 Define the botanical term ephemeral with two examples. SV SM

Answer 26

A plant that has several life cycles in a growing season and can increase in numbers rapidly.

• Senecio vulgaris*
• Stellaria media*

Question 27

1.4 Define the botanical term perennial with two examples.

Answer 27

A perennial is a plant that lives more than two years. The term is also widely used to distinguish plants with little or no woody growth (secondary growth in girth) from trees and shrubs.

Alchemilla mollis

Aster amellus ‘King George’

Question 28

1.4 Define the horticultural term tender perennial with two examples.

Answer 28

A tender perennial is a perennial grown in a place where the winters are too cold survive outside, so they are brought indoors during the winter.

Gazania ‘Tiger Stripes’

Pelargonium‘Mabel Grey’

Question 29

1.4 Define the horticultural term half hardy annual with two examples.

Answer 29

A half hardy annual is an annual sown under protection early in the season then planted out.

• Cosmos bipinnatus ‘Rubenza’
• Tropaeolum minus (Nasturtium)

Question 30

1.4 Define the horticultural term hardy annual with two examples.

Answer 30

A hardy annual can survive some frosts and can be started from seed outside in spring, before the last frosts of the year.

• Calendula officinalis (pot marigold)
• Nigella damascena (love-in-a-mist)

Question 31

1.4 Define the term shrub with two examples.

Answer 31

A woody plant generally smaller than a tree. Shrubs have multiple stems emerging from one base near ground level. They can be deciduous or evergreen.

• Buxus sempervirens
• Cornus alba ‘Bloodgood’

Question 32

1.4 Define the term tree with two examples.

Answer 32

A tall woody plant with a single stem or trunk that branches at height. Trees can be deciduous or evergreen.

• Acer campestre
• Quercus robur

Question 33

1.4 Define the botanical term herbaceous with two examples.

Answer 33

• lack persistent above ground growth
• do not form woody stems
• Annual: 1 year life cycle - Limnanthes douglasii
• Biennial: 2 year life cycle - Digitalis purpurea
• Perennial: Living for more than 2 years - typically dying back in autumn to ground level or underground resting buds, starting into growth again in spring - Alchemilla mollis

Question 34

1.4 Define the botanical term woody with two examples.

Answer 34

• Divided into trees and shrubs
• Shoots are durable and survive over a period of years
• Deciduous and evergreen
• Quercus robur (oak tree)
• Buxus sempervirens (box shrub)

Question 35

1.4 Define the botanical term evergreen with two examples.

Answer 35

• Retains leaves in all seasons
• Leaves of evergreens usually are thicker, darker green and more leathery than those of deciduous plants
• Hedera helix ‘Saint Agnes’
• Taxus baccata

Question 36

1.4 Define the botanical term semi-evergreen with two examples.

Answer 36

A plant that retains some of its leaves through the year but may shed most leaves under severe weather conditions such as extreme cold or drought.

• Lonicera japonica ‘Mint Crisp’
• Dryopteris cycadina

Question 37

1.4 Define the botanical term deciduous

Answer 37

A plant that sheds all of its leaves at once, often at the end of the growing season.

• Acer campestre
• Quercus robur