Unit 2 topic 1 Flashcards
State the primary purpose of leaves
To create food for the plant through photosynthesis
Describe the process that helps to cool the leaf in heat
In dry air, water vapour moves out of the leaf to try and equalise the humidity inside the leaf and the dry air outside it. Diffusion
Describe the leaf adaptation to reflect sunlight & 3 plants that have adapted to do this
silver hairs reflect strong sunlight
-Stachys byzantina
-Senecio cineraria ‘Silver Dust’
-Senecio candidans ANGEL WINGS (‘Senaw’ pbr)
What is a leaf adaptation against herbivory?
Prickly leaves. Ilex aquifolium
What is a leaf adaptation against water loss?
Reduced leaf area. Lavandula spp
What is a leaf adaptation against drought?
Thickened leaves to act as water storage. Aloe vera
What is totipotency?
Every part of the plant contains the genetic information to become any other part of the plant. DNA in the cell nucleus contains all the information to become any part of the plant tissue.
Why is totipotency important to horticulturists?
It makes cloning of specific traits/habits in plants possible. Cloning of desired plants from leaves, stems, roots.
List 5 purposes of the plant stem
- supports the plant
- Positions leaves in optimal place to capture sunlight
- Holds up flowers for pollinators
- Acts as a conduit between roots (where minerals and water are) to leaves
- Link between leaves (where food is manufactured) and all the growing parts of the plant (roots, shoots, flowers, fruit), where food is needed
Explain secondary thickening
In eudicots, the vascular bundles gradually join up to form complete rings with xylem on the outside and phloem on the inside. As the plant grows, a new layer of xylem is laid down inside the cambium. Year after year, new layers of x&p are laid down. The phloem pushes out and the xylem is compressed inwards and forms the ring within a tree trunk. The epidermis thickens and becomes corky protective bark.
Describe a stem defense adaptation
Short branches arising from auxillary buds evolve into thorns. Stops herbivory.
Pyracantha rogersiana
What are tendrils and twining stems?
Stems elongate and support themselves through other plants.
Lonicera periclymenum. Wisteria spp.
What are stolons?
Lateral stems that grow horizontally over the soil surface, producing adventitious roots at some nodes and adventitious buds and subsequently new plants along its length.
Fragaria x ananassa
Ranunculus repens
What are tubers?
organs formed at the end of rhizomes which store food over winter and develop into independent plants the following year.
Solanum tuberosum
What are runners?
Over ground stolons that only put down roots at its tip.
Rubus cockburnianus ‘Wyevale’
What are glandular hairs/ducts?
stems that contain essential oils that make them unpalatable to grazing.
Salvia nemerosa ‘Cardonna’
What is a stem adaptation against cold?
Stems are kept below ground so dormant buds are protected from cold damage in winter.
Anemone nemerossa (rhizome)
List 5 ways stems can be used for propagation
- Soft wood cutting taken from young material in active growth - Salvia
- Hardwood cuttings from longer sections of a one year old stem. Quercus
- Semi-ripe cuttings from deciduous material late summer through the autumn. Lavendula
- Layering producing roots when nodes on the branch or stems touching the ground. Cornus sanguinea
- Air layering by placing a wound in a stem and then wrapping in spaghnum moss to encourage new roots. The shoot is severed up to a year later and grows away on its on roots. Ficus elastica
What is the primary function of roots?
To take up water.
Also, to anchor the plant, bring in nutrients and help plants survive winter cold
What are fibrous roots?
In monocots. Multi-branched and occupying a large area in the upper top soil. Helps to prevent soil erosion. Ammophila arenaria
What are tap roots?
In eudicots. main roots that grown deep into the ground to source water and anchor the plant. Quercus alba
What are foraging roots?
Roots spread out over a wide area in the soil. Also fine hairs increase the surface area which can absorb water. Cacti
What is tropisms?
Growth movement in a specific direction. The radical emerges from the seed first and grows downwards.
What are adventitious roots?
Roots above ground. Stilt roots - Zea mays
Prop roots - Ficus benghalis
What are tubers?
Thickened lateral roots that have adapted to store nutrients over the winter. Dahlias
What are pneumatophores?
Roots that emerge above ground in water logged soils or bogs. Taxodium distichum
What are adventitious buds?
Develop from shallow roots creating ‘suckers’ Cornus or Rhus typhina
What are root nodules in legumes?
Rhyzobium bacteria enters through root hairs and causes cells to divide forming outgrowths or root nodules. The bacteria feeds off of sugars from the plant and also fixes nitrogen from the air so it is accessible by the plant.
What are aerial roots?
Roots that develop from a stem. They help support the plant in growing towards the sunlight. Hedera helix
Describe the symbiotic relationship between plants and fungi
Network of fungal filaments spread through the soil and reaching areas the plant roots cannot. They bring in nutrients like phosphorus in exchange for sugars produced in photosynthesis
How are roots used in propagation?
substantial one-year roots are cut into sections and inserted vertically into the soil (right way up!), thinner roots can be laid horizontally across the soil. The cuttings act as a food store, first new shoots and then eventually new roots are formed from the top of the cutting.
Describe a raceme
Flowers are attached to main stem by short stalks. Main axis continues to grow and produce flowers.
Example: Genista racemosa
Describe a corymb
All pedicels grow different amounts to reach the same level. Forms a platform for insects to land.
Example: Sambucus nigra
Describe a simple umbel
Pedicels arise from the same point.
Example: Agapanthus spp
Describe a panicle
Each branch is a raceme and on each the flowers open from the base of the raceme.
Example: Astilbe arendsii
Describe a cyme
The main axis forms a flower at its tip; then lateral buds form panicles of flowers which open from the top downwards.
Example: Begonia semperflorens
Describe a capitulum
Daisy-type flower: Showy ray florets attract pollinators to the fertile disc florets which are arranged in a mass for efficient pollen transfer.
Example: Helianthus annuus
Describe a verticillaster
whorled; flowers borne in rings at intervals up the stem, lower rings opening first. Tip continues to grow, producing more whorls.
Example: Stachys byzantina
What is the reason for flowering time adaptations in flowers?
To take advantage of pollinators available at the time of flowering and to attract the most pollinators in order to promote cross-pollination.
What is dichogamy?
When the stamens and stigma mature at different times on a flower.
What is protandry?
When the stamens ripen, produce and release pollen before the stigma of the flower is ready to accept pollen.
Example: Chamaenerion augustifolium
What is protogyny?
When the stigma matures first and is pollinated before the plant produces its own pollen.
Example: Magnolia grandiflora
Name a flower with ultra violet markings to attract bees
Alstroemeria spp
Name a flower that uses scent to attract pollinators
Daphne spp
Name a flower with nectaries
Tricyrtis formosana
What is a hermaphrodite flower?`
Perfect or entire. Having both male and female parts
What is an imperfect flower?
Having only male or female parts
What is a monoecious plant?
Having separate male and female flowers on the same plant.
Example: Juglans regia
What is a dioecious plant?
Male plants and female plants. Enforced cross-pollination.
Example: Ilex crenata
Define cross-pollination
Pollen from one plant lands on the stigma from another of the same species
Define self-pollination
Pollen from one plant lands on the stigma of the same exact plant. Not advantageous as it doesn’t bring in new genetic material
How can a flower adapt to encourage cross-pollination?
Heterstyly: flower structure differs in placement of stigma and anthers between clumps of primula
Characteristics of insect pollinated plants
Large flowers
Brightly coloured petals
Anthers inside the flower structure
Sticky and relatively large pollen grains
Landing pads or large inflorences
Scented
Nectaries and nectar guides
Characteristics wind pollinated plants
small flowers
Green or white flowers
Loosely attached anthers, catkins
Light and smooth pollen grains
Large feathery stigmas hanging outside the flower
Basically unscented
Large quantities of pollen
Taller than insect pollinated plants
What is the purpose of seeds?
To ensure the continuation of the species
Why do some plants produce large quantities of small seeds and others small quantities of large seeds?
Small seeds will fail in adverse conditions as they do not have a large store of food. Producing a vast number ensures that a number of them will germinate. Large seeds have a better chance of germinated in adverse conditions.
What does a viable seed need to be able to germinate?
Water/moisture
Light
Oxygen
Temperature (warm)
What plant releases seed into the wind
Nigella damascena releases seed via capsules
What plant uses an explosive mechanism to release seed?
Cardamine hirsuta releases seed when touched
What plant uses twist and split to release seed?
Ulex europeans
What plant uses animals to transport seed?
Galium aparine
What plant relies on animals to eat and digest its seeds?
Berberis thunbergii
Describe dormancy
Reduced metabolic activity
4 ways dormancy is imposed on seeds
Seedcoat prevents water from entering
Seedcoat blocks oxygen
Embryo contains inhibitor chemicals
Embryo not fully formed when seed is shed and needs time to form before germination
What is stratification?
Chilling seeds to break dormancy
What is scarification?
Breaking down the seed coat to allow water and gases in
What is washing and soaking?
Removing inhibitors in fruits to let seeds germinate
How do you store orthodox seeds?
They are dry and can be stored at cool temperatures for many years. Best stored in a fridge in paper bags/envelopes within a plastic bag.
How do you store recalcitrant seeds?
They are high in fats/oil and do not store well. Can be kept for a short time and must not dry out. Store in a cool place in plastic bags of moist sand/peat substitute/fine vermiculite
Name a ground-hugging plant
Saxifraga spp
Name a dwarf or sub-shrub
Erica cornea
Name a ground cover plant
Vinca major
Name a herbaceous perennial
Echinacea pupurea
Name a seasonal ephemeral
Galanthus nivalis
Name an evergreen perennial
Epimedium x rubrum
Name a tender perennial
Canna indica
Name a deciduous tree
Cornus kousa
Name an evergreen tree
Thuja plicata
Name a shrub
Buxus sempervirens
4 key essentials of a Persian garden
water, shade, flowers, music
4 different types of enclosed gardens following Roman period
Physics, Mary, Courtly, hortus
Describe a paradise garden
Verdant, flowing springs, stimulate all the senses, dates & pomegranates, strong geometric forms, ornamental motifis - esp flowers, not people
Key features of a Renaissance garden
Reflect the magnificence of the owner, located on a hillside with natural springs to power the fountains, lots of statuary, exotic plantings from explorers, vast retaining walls, staircases
Key features of a Baroque garden
Strong main axis, cascades/features at end of every vista, walks of pleached trees, mazes, arbours, topiary, knot gardens
Key features of English Landscape Gardens
William Kent (Roushan Park), Charles Bridgeman (Haha), Lancelot Brown (Blenheim), Humphry Repton (Stowe). Less expensive to maintain, natural, carriage paths hidden, vistas and focal points, no clipped topiary
Key features of a Picturesque garden
Idealised the wilder aspects of nature. Echoed romanticism in poetry at the time. Lake District, Central Park. Uvedale Price, William Gilpin
Key features of a Gardenesque garden
John Louden. Individual plants and trees most important. Serpentine mounds to display trees. Derby Arboretum
Key gardens designed by Sir Joseph Paxton
Chatsworth House, Birkenhead Park, Hesketh Park, Peoples Park, Princes Park
Why did bedding schemes become popular after 1845?
Glass tax had been abolished, making greenhouses more affordable
Key points of William Robinson’s Wild Garden style
All hardy plants, allowed to grow to natural form and size, no straight lines or hard edges, subtle flower colours, foliage of equal importance to flowers, long grass, meadows
5 of Robinson’s wild gardens
Gravetye, Bodnant, Castlewellen, Knight Shayes, Mount Usher
Key features of Arts and Crafts gardens
Celebration of local crafts people, harmonizing, Dovecotes, Garden houses, pergolas, unity of house and garden, Drifts of colour. Sissinghurst - Vita Sackville-West, Kelmscott - William Morris, Hidcote - Lawrence Johnston
Define ‘plant association’ in ecological terms
A group of plants which naturally occur together on a site
Define ‘plant association’ in horticultural terms
plant groupings which work well together, complimenting each other in leaf form, growth habit and height
What are harmonious colours?
Adjacent on the colour wheel
What are complimentary colours?
opposite on the colour wheel
What are triadic colours?
3 colours equally spaced on the colour wheel
What plant can give vertical interest?
Phyllostachys nigra, Phormium tenax
What plant can give a garden structure?
Taxus baccata, Buxus sempervirens
Name plants for wildlife
Crataegus mongyna (shelter, pollen, berries, nesting sites), Cardamine pratense (food source for orange-tipped butterfly), Quercus robur (supports 280 species of insect)
Name a plant for a horizontal plane
Vinca major, Cornus controversa ‘variagata’
Name a plant for vertical lines
Dicksonia antarctica, Phyllostachys nigra
Name a plant for screening
Tilia spp, Taxus baccata
What is an ecosystem service?
Benefits to humans provided by the natural environment
What plants improve air quality?
Cotoneaster franchetti, Planatus trees
What plant is good for mitigating water pollution?
Arundo donax, reeds to filter pollutants out of waterways and runoffs
What are good for crop pollination?
Lathyrus odoratus planted with runner beans, Hedera helix allows habitats for pollinators
What can control erosion on slopes?
Ammophila arenaria (grass, monocot with shallow fibrous roots)
What are the intangible benefits of plants>
Soothing sounds of rustling grasses, Miscanthus sinensis. Soothing sweet scent of Sarcococca confusa
How can plants help with climate mitigation?
Trees to shade urban areas, roof gardens & green roofs can help insulate buildings as well as slow down rain fall, Long-lived plants like trees are a carbon sink, raingardens and swales absorb water slowly from hardscaping (persicaria, fillependium)
What is an edible landscape?
Food grown outside of large scale farming
How can you grow herbs for an edible landscape?
between paving stones, in a gravel garden, in a traditional border, pots/containers
How to grow vegetables?
Allotment beds, not more than 1.5 meters wide, raised beds, pots/containers/grow bags
What is a Potager garden?
ornamental kitchen garden, edible flwoers, herbs and vegetables planted within a formal framework. Rosemary Verey -Barnsley House, Chateau de Villandry. Decorative as well as productive
Describe ‘Incredible Edibles’
2007 in West Yorkshire - volunteers reclaim unused urban spaces/street corners, planters, and grow fruit/veg for anyone to pick and enjoy. 120 in England today, 700 worldwide
What is Crop Rotation?
changing the crops grown in a bed each year. Large Bottoms Pop Out Regularly. Legumes, Brassicas, Potatoes, Onions/roots. Legumes will fix the nitrogen. Rotating stops the build-up of crop specific pests and diseases
Different growing systems for vegetables
Traditional (rough digs, top dressing of fertilizer)
Organic (Pyrethrum pesticide, hand weed controls)
No dig (large supply of organic matter, Charles Dowding)
Biodynamic (Steiner, rhythm of planets/moon)
name an annual bedding plant
Cosmos bipinnatus
hardy annual
Nigella damascena
tender perennial
Pelargonium zonale
short lived perennial
Erysium cheiri
bulb
Tulipa ‘Queen of the Night’
What plants are in a traditional summer bedding display
Lobelia erinus, Ageratum houstonian, Salvia splenens, Pelargonium zonale, Standard fuschia. All require regular watering schemes, come packed in plastic and will be thrown out at the end of a season. But they are pleasant for people and good for pollinators. Trailing forms of lobelia and Fuschia for containers and hanging baskets
Positive and negative aspects of an annual border
temporary, cheap and a mass of colour - good for pollinators and filling in gaps while perennials establish. Can be very drought tolerant. Wasteful as they do not survive a frost. Cosmos, Calendula officinalis
Positive/negatives of winter/spring bedding display
Provides flowers for pollinators when little else is flowering, always discarded at end of season, very wasteful - plastics.
What is an annual meadow?
Papavar rhoeas, Centaura cyanus, Barley/wheat. Sown onto bare soil, plants flower within 3 months, leave them to self-seed. Seeds involve less packaging than plants, urban spaces with flowers are less often vandalized. A pictorial meadow includes annuals and perennials. Few negative aspects
