Horticultural Plant Names and Plant Life Cycles

Question 1

1.1a State 5 key characteristics of conifers

Answer 1

Conifers are :

1. Mostly evergreen
2. Woody (trees and shrubs)
3. Cone bearing male (pollen) and female (seed bearing) cones with
4. naked seeds - Gymnosperm
5. Perennial life cycle

Question 2

1.1b State 4 key characteristics of flowering plants

Answer 2

Flowering plants - Angiosperms are:

1. evergreen or deciduous
2. herbaceous or woody
3. produce flowers & enclosed seeds
4. All life cycles: Ephemeral, Annual, Biennial, Perennial

Question 3

1.12a Describe the characteristics of a typical monocotyledonous plant to include:

1. root inc. internal arrangements of vascular bundles
2. stem inc. internal arrangements of vascular bundles
3. leaf
4. flower
5. seed

Answer 3

1. Monocot roots (inc vascular bundles): short lived primary root, replaced by adventitious roots, forming fibrous root system. Vascular tissue (stele) in the root has many arms. No vascular cambium in Monocots, therefore No secondary growth and limited increase root girth
2. Monocot stem (inc vascular bundles): vascular bundles scattered inside. No defined cortex or pith. No vascular cambium in Monocots, therefore No secondary growth and limited increase in stem girth
3. Monocot leaf: Typically parallel veins, narrow linear shape, smooth margins, petiole (leaf stalk) infrequent
4. Monocot flower: Flower parts usually in 3’s or multiples of
5. Monocot seed: 1 cotyledon, seed leaf

• Typically small herbaceous plants (except palms and bamboos)
• Monocots are typically wind pollinated

Question 4

1.12b Describe characteristics of a typical dicotyledonous plant to include:

1. root inc. internal arrangements of vascular bundles
2. stem inc. internal arrangements of vascular bundles
3. leaf
4. flower
5. seed

Answer 4

1. Dicot root (inc vascular bundles): Both fibrous and tap root systems, often tap root where primary root typically persists with smaller lateral roots. root vascular bundles located in the (stele) is star shaped with up to 7 arms. Vascular cambium present in Dicots, a lateral meristem which increases the root girth through secondary growth
2. Dicot stem (inc vascular bundles): stem Vascular bundles are arranged cylindrically around the outer portion of the stem. Vascular cambium present in Dicots, a lateral meristem which increases the stem girth through secondary growth
3. Dicot leaf: reticulated (network) veins, many different shapes and margins
4. Dicot flower: Flower parts usually in 4’s and 5’s or multiples thereof, often 4 or 5 seed chambers in fruit
5. dicot seeds have two cotyledons, seed leaves

• May be small or large, woody or herbaceous species, with woody stems showing annual rings and bark
• Dicots maybe wind or insect pollinated

Question 5

1.21 State the reasons why botanical names are important

Answer 5

Binomials names are / can:

1. stable
2. unique therefore unambiguous
3. internationally understood
4. provide information about a species
5. plant may not have a common name (new to science)
6. avoids confusion plant may have more than one common name

Question 6

1.22a Describe the binomial system of naming plants and state how they are written with reference to 3 plant examples

Answer 6

The binomial system is a method of naming plants which has two parts for each plant name. The first part of the plant name relates to the genus which the plant belongs to and the second part relates to the species.

Conventions: The generic name starts with an upper case letter, the specific epithet is written all in lower case letters, and the whole plant name is typed in italics or underlined if hand written.

1. Quercus robur
2. Fagus sylvatica
3. Acer palmatum

Question 7

1.22b State the meaning of the term ‘genus’

Answer 7

A genus is a group of plants containing one or more species, sharing a number of significant physical attributes that may or maynot be obvious

Question 8

1.22c State the meaning of the term ‘species’

Answer 8

A species is a group plants within a genus, sharing many key characteristics, capable of breeding together to produce viable offspring

Question 9

1.23a Describe the naming of cultivated plants and state how it is written with reference to 3 plant examples.

Answer 9

The naming of cultivated plants follows the conventions of the binomial system for generic and specific epithets.

To make it stand out from the purely botanical part of the name, the cultivar name is enclosed in single quotation marks and is not written in italics It appears as upper or lower case roman type.

1. Erica carnea ‘Ann Sparkes’
2. Viburnum opulus ‘Aureum’
3. Cornus alba ‘Kesselringii’

Question 10

1.23b State the meaning of the term ‘cultivar’

Answer 10

A cultivar is a cultivated variety of a species. They have not usually arisen in the wild and must be maintained in cultivation either by specific breeding programmes to produce seed or by vegetative propagation.

1. Erica carnea ‘Ann Sparkes’
2. Viburnum opulus ‘Aureum’
3. Cornus alba ‘Kesselringii’

Question 11

1.31a Describe the seed stage in the life cycle of a plant and its significance to horticulture

Answer 11

Descripton: Typically a plant’s life begins with fertilization and the development of an embryo within a seed.

Significance to horticulture: Seed is a dormant embryonic plant and has a low rate of respiration. The embryo is enclosed in a testa (tough coat) and has a food store in the cotyledons or the endosperm (tissue that surrounds and nourishes the embryo)

Question 12

1.31b Describe the juvenile stage in the life cycle of a plant and its significance to horticulture

Answer 12

Description: Juvenile (vegetative) stage commences with germination and seedling growth which has a tendency to rapid vegetative growth, and is non-reproductive.

• Significance to horticulture: juvenile plants will not set seed but juvenile growth typically related to rooting success in cuttings.
• Differing leaf shape between juvenile and mature growth e.g. Eucalyptus
• Different growth habit may differ between juvenile and mature growth e.g. Hedera helix
• Leaf retention can be characteristic of juvenility e.g. Fagus sylvatica
• Pruning for juvenility - coppicing Cornus spp. for winter stem colour

Question 13

1.31c Describe the adult stage in the life cycle of a plant and its significance to horticulture

Answer 13

Description: Adult (reproductive) plant or growth fully developed and able to flower and bare fruit / seeds

Significance to horticulture:

• Sexual reproduction occurs involving flowers fruit and seed production
• Adult growth may not make good material for cuttings
• Adult plants are often the most desirable commercially

Question 14

1.31d Describe the senescence stage in the life cycle of a plant and its significance to horticulture

Answer 14

Description: Senescence (slow tissue death) refers to the period of time between adulthood and death of the plant. Stage after flowering and fruiting, where growth has ceased and gradual deterioration occurs.

Significance for horticulture:

• flowering and fruiting ceases
• Senescence most obvious in ephemeral, annual and biennial plants. Senescence still occurs in perennials but this may be over the course of a few years or thousands of years.
• Senescence also applies to changes which take place through the year and are repeated each year in leaves e.g. leaves show autumn colour and leaf abscission
• Senescence in fruit is where fruits deteriorate and seeds ripen before being shed. Growers aim to harvest fruit before this point and arrest further development through range of post harvest techniques including reduced temperatures & controlled atmosphere reducing oxygen and enriching oxygen to limit respiration

Question 15

1.31e Describe the death stage in the life cycle of a plant and its significance to horticulture

Answer 15

Description: All metabolic processes cease, including photosyynthesis, respiration leading to cell death

Significance for horticulture:

• Death at the end of the season in annuals, or at the end of the plants life in perennials
• Death of the plant organ such as the leaf where this undergoes senescence.
• plant matter is returned to the soil to be taken up by and sustain future plants

Question 16

1.41a Define the botanical term ‘annual’ and the horticultural meaning of ‘annual’. Two examples should should be know for each term

Answer 16

• Botanical Annuals: are plants that go through their entire life cycle in one growing season.
• Horticultural Annuals: are plants which are grown or treated as annuals for practical purposes even though they may posses a different life cycle botanically.

1. Cosmos bipinnatus
2. Limnanthes douglasii

Question 17

1.41b Define the botanical term ‘ephemeral’. Two examples should should be know for each term

Answer 17

Ephemeral: Ephemerals are plants that can often have several life cycles in a single growing season and can increase in number rapidly

1. Senecio vulgaris
2. Cardamine hirsuta

Question 18

1.41c Define the botanical term ‘biennial’ and the horticultural meaning of ‘biennial’. Two examples should should be know for each term

Answer 18

• Botanical Biennials: are plants whose life cycle spans two growing seasons. In the first season plants typically germinate and produce vegetative growth after which they become dormant,usually to survive adverse conditions. The following season, usually after a period of vegetative growth, they flower, produce seed and die
• Horticultural Biennial: Some true biennials are grown and treated as annuals e.g. Daucus carota

1. Digitalis purpurea
2. Echium vulgare ‘Blue Bedder’

Question 19

1.41d Define the botanical term ‘perennial’ and the horticultural meaning of ‘perennial’. Two examples should should be know for each term

Answer 19

Botanical Perennial: A plant living through more than 2 years. They may become dormant from year to year, but come back into growth during favourable conditions, and usually flower and fruit each year.

Horticultural Perennial: to a gardener the term ‘perennial’ usually means a herbaceous perennial; any non-woody plant that a botanist would call a herb.

1. Helleborus foetidus
2. Bergenia pacumbis

Question 20

1.42a Define the botanical terms ‘herbaceous’. Two examples should should be know for each term

Answer 20

Herbaceous plants have no persistent woody stem above ground, instead they typically die down to a hardy owner wintering structure from which they regrow the following year. Herbaceous plants do not experience secondary thickening

1. Paeonia lactiflora ‘Lord Kitchener’
2. Hosta venusta

Question 21

1.42b Define a range of botanical and horticultural terms relating to plant growth Define the botanical terms ‘woody’. Two examples should should be know for each term

Answer 21

Woody plants are those which have a permanent frame work of branch and stem structures containing lignified tissue which persists above ground from year to year.

Accumulative growth?

1. Quercus robur
2. Fagus sylvatica

Question 22

1.42c Define the botanical terms ‘evergreen’. Two examples should should be know for each term

Answer 22

Evergreen plants retain some their foliage / leaves throughout the year and into the following growing season.

1. Clematis cirrhosa
2. Sequoia sempervirens

Question 23

1.42d Define the botanical terms ‘semi-evergreen’. Two examples should should be know for each term

Answer 23

Semi-evergreen plants are plants which are evergreen by inclination, but are sensitive to cold. Therefore in mild conditions they will retain the majority of their leaves, however during adverse conditions will drop their leaves

1. Daphne x Burkwoodii ‘Somerset’
2. Cotoneaster sternianus

Question 24

1.43a Define the horticultural term ‘tender perennial’. Two examples should should be know for each term

Answer 24

Tender perennial: a plant that live for more than two years but which cannot survive frost. Tender perennials need to be in a frost free environment over winter and only put outside when all danger of frost has passed

1. Musa basjoo
2. Canna indica

Question 25

1.43b Define the horticultural term ‘half hardy annual’. Two examples should should be know for each term

Answer 25

Half hardy annual are frost tender, therefore are sown under protection early in the season then planted out after the risk of frost has passed

1. Cosmos bipinnatus ‘Apollo Pink’
2. Petunia axillaris

Question 26

1.43c Define the horticultural term ‘hardy annual’. Two examples should should be know for each term

Answer 26

Hardy annual is sown in situ, directly into the soil where they are to flower

1. Eschscholzia californica
2. Lathyrus odoratus ‘High Scent’

Question 27

1.44a Define the term ‘tree’. Two examples should should be know for each term

Answer 27

Tree: a perennial, woody plant, with secondary thickening, with a clear main trunk. Typically tall, being at least 2 to 3 metres in height

1. Quercus robur
2. Fagus sylvatica

Question 28

1.44b Define the term ‘shrub’. Two examples should should be know for each term

Answer 28

Shrub: a self supporting woody plant branching at or near the base or with several stems from the base. Typically quite short being generally less than 2 metres in height.

1. Choisya ternata
2. Cornus mas