PS 3 Describe Stages Of Plant Growth Flashcards
Describe the stages of the life cycle of a plant
Plants can be categorised according to how they complete their life cycle
Their are 5 distinct stages in the life cycle of flowering plant
SEED
The Embryonic plant in the seed is waiting for suitable conditions to occur before it germinates
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)
JUVENILE / VEGETATIVE
the plant produces vegetative growth but has not yet reached maturity and cannot flower or reproduce sexually at this stage
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
ADULT
The plant has reached maturity and is capable of flowering and sexual reproduction
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
SENESCENCE
The plant is in decline, this stage precedes death. Physiological processes are slowing down , change of colour, lack of vegetative growth, seeds are mature and dispersed, sexual reproduction finishes.
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
DEATH the end of the plants life cycle All processes stop completely Can not absorb oxygen Cannot take up sugars 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
List the stages of plant life cycle
SEED JUVENILE/VEGETATIVE ADULT SENESCENCE DEATH
Define Growth
Growth may be defined as the progressive increase in size and volume, and DEVELOPMENT as changes in plant form as a result of growth elk differentiation
Define the botanical terms “annual’
Define horticultural meanings of annuals
Botanical terms
Annual plants germinate, grow, flower, set seed and die all within 12 months
Horticultural terms
Horticultural Annuals: are plants which are grown or treated as annuals for practical purposes even though they may posses a different life cycle botanically.
NEED TYPES
Define botanical terms for ‘Ephemeral’
Ephemerals can complete several life cycles in 12 months
In particular weeds, - examples are
Stellaria media (chickweed)
Senecio vulgaris (groundsel)
Define the botanical terms biennial
Define the horticultural meaning of biennial
A true biennial lives for 2 years. The first years growth is usually vegetative (roots, stems and leaves) and in the second year the plant flowers, sets seed and dies.
Lots of winter bedding plants are Biennials
Examples: Digitalis pupurea (foxglove) Dipsacus fullonum (teasel)
Horticultural biennial meaning:
Are botanically perennial but are grown like biennials and when they have flowered once are removed and allowed to die eg;
Erysimum cheiri (wallflower)
Myosotis sylvatica (forget -me-not)
Define botanical term Perennial
Define horticultural meaning of perennial
Perennial species is a group of plants which live for more than 2 years and the surviving organ is the root system
Horticultural Perennial: to a gardener the term ‘perennial’ usually means a herbaceous perennial; any non-woody plant that a botanist would call a herb.
Describe the botanical term ‘herbaceous ‘
Herbaceous perennials are a group of plants which never produce wood , they die back for the winter and their surviving organ is the root
Sedum spectabile (ice plant ) Echinacea purpurea (cone flower)
Define the botanical terms ‘woody’
Woody perennials are a group of plants that live for more than 2 years and they produce wood
Woody- a plant that has wood in its stems or roots
Fagus sylvatica
Hydrangea arborescens “Annabelle”
Define the botanical term ‘evergreen ‘
A plant that has green leaves all year round
Ilex aquifolium (holly) Bergenia cordifolia (elephants ears)
Define the horticultural terms tender perennial
A group of plants from hot climates which cannot survive temperatures below 1degree c Canna indica (Indian shot plant)
Pelargonium zonale (bedding geranium)
Define the horticultural term ‘half hardy annual’
A group of annual plants that complete their life cycle in 12 months and can survive temps up to -5
Can be sewn under protection early season (March/April) then planted out when danger of frost has passed
Tagetes patula (French marigold) Lobelia erinus (bedding lobelia)
Define the horticultural terms ‘hardy annual’
Is a group of annuals that complete their life cycle in 12 months but can withstand temperatures to -10 , and can be sewn out in situ as early as March
Helianthus annuus (sunflowers) Calendula officinalis (English marigold)
Define the terms ‘shrub’
A woody perennial plant with more than one stem growing from ground level
Cornus alba (red dogwood)
Magnolia stelata
Rosa canina (dog rose)
Define the term ‘tree’
Tree is a woody perennial which produces 1 stem /trunk above the ground Quercus robur (English oak) Fagus Sylvatica (European beech)
