Leaf Adaptations Flashcards
What is a trichome?
A small hair or other outgrowth from the epidermis of a plant, typically unicellular and glandular.
List 8 leaf adaptations
- Hairs (trichome)
- Essential Oils (Glandular trichome)
- Upright orientation and reduced size
- Thick waxy cuticle
- Reduced stomata size or fewer stomata
- Spines
- Narrow leaves
- No leaves
How do hairy leaves protect the plant?
- Reduce water loss
- Provide resistance of air movement on leaf surface and stomata
- Shade leaf
- Reflect solar energy
- Protects from insects/pests.
Stachys byzantina
What is the use of glandular trichomes?
- Essential oil on leaves
- Deters insects/herbivores/pathogens
Lavandula angustifolia
Adaptation of leaf and plant size?
Upright orientation and reduced leaf size.
Requires less water as reduced.
Adaptation of stomata?
Reduced number of stomata size
Fewer stomata on the leaf
Sunken stomata
Less water evaporation
What are Spines
Leaves that have adapted to minimize the surface area.
Succulent
Waxy cuticle
Sharp “teeth” at edges and tip
Stops animals from obtaining moisture from the plant.
Agave ovatifolia
Ulex europaeus (GORSE)
Explain what adaptation narrow leaves have
Stomata is not exposed as it’s inside the leaf.
Inrolled margins - narrow gap at the bottom of the cross section.
EXAMPLE: Ammophila arenaria (marram grass)
Do some plants have no leaves?
YES. These plants have adapted and have no leaves. They photosynthesize through their stems.
Cacti leaves are spines. Stomata is sunken and opens at night.
Succulents have collapsible cells which holds water.
Example: Genista spp. (Broom)
Opuntia microdasys has irritating leaves
What is CAM
Crassulacean Acid Metabolism
Photosynthesis during day but stomata only open at night.
Plants have a slow metabolism
Plant stores C02 at night as malic acid, then can photosynthesize during the day.
What is an Aerole?
Small raised cushion where spines and flower and branches grow.
Only found in a cacti (if NO aerole, not a cacti)
Oreocereus spp.
How have some plants adapted to drought with examples?
- Succulence: Ability to collect water (agave americana)
- Spherical or columnar stems (Echinocactus grusonii)
- Leaf spinescence of cacti (leaf=spine-aeroles)
- Cacti pubescence (HAIRS) found in alpine area)
- Root adaptations - spread far distances ( to absorb H20 quickly)
- CAM
How have aquatic plants adapted to their environment?
Roots are not needed to collect water used for anchorage only. They are thin and poorly developed.
Stems are flexible as held up by water
Thin or no waxy cuticle
Aeenchyma cells for buoyancy
Water pollinated
What is aerenchyma
Modified parenchyma that form a spongy tissue creating air filled cavities that allow gas exchange within the plant and aid flotation in leave of aquatic plants.
EXAMP:ES:
Nymphaea alba
Trapa nutans
Nelumbo nucifera
What does aerenchyma provide for the plant?
Buoyancy
Respiration
Nelumbo nucifera - lotus leaf. Held up by air spaces in stem.