LEAFNature’s Solar Panel
LEAF
Leaf stalk
Petiole
Leaf lacking petiole
Sessile
Leaf blade
Lamina
Appendages at base of petiole
Stipules
Network of veins
Vascular bundles
ARRANGEMENT
Alternate
One leaf per node
Alternating along stem
Most common
Opposite
Two leaves attached to a node
Whorled
Three or more attached to node
SIMPLE LEAF
One blade on petiole
COMPOUND LEAF
Multiple leaflets on petiole
Pinnately compound
Leaflets attached to extended petiole
Rachis
Bipinnately compound
Multiple rachis
COMPOUND LEAF
Multiple leaflets on petiole
Palmately compound
All leaflets attached to end of petiole
Palm
VEINS
Netted vein arrangement
Dicots (broadleaves)
Parallel vein arrangement
Monocots (grasses)
Only tree to have fan arrangement
Ginkgo
PHOTOSYNTHESIS
Capture light energy
Store energy in form of carbohydrates
Water
Carbon dioxide
STOMATA
Openings on lower surface of leaf
Stomata
Guard cells open and close
Regulated by potassium (K)
Inflated guard cells open
Deflated guard cells closed
STOMATA
Gas exchange
Carbon dioxide in
Oxygen out
Transpiration
Water vapor evaporation
Cooling plant
RESPIRATION
Consumption of carbohydrates
Growth
EPIDERMIS
Outer layer of cells
Epidermis
Waxy cutin
Cuticle
Thicker in the presence of pollutants or pests
Epidermis on top and bottom of leaf
Stomata mostly on bottom
MESOPHYLL
Cells between upper and lower epidermal layers
Parenchyma cells with cholorplasts
Cholorenchyma
MESOPHYLL
Upper mesophyll
Palisade mesophyll
Two rows
Compacted barrel-shaped chlorenchyma cells
Majority of photosynthesis
MESOPHYLL
Lower mesophyll
Spongy mesophyll
Loose arranged
Abundant air spaces
Primarily for gas exchange
VEINS
Vascular bundles
Xylem
Phloem
Contained in a thick wall of parenchyma cells
Bundle sheath
SPECIALIZED LEAVES
Shade leaves
Lower part of tree
Understory
Larger
Thinner
Less sunlight and heat
SPECIALIZED LEAVES
Arid leaves
Thicker
Fewer stomata
Reduce transpiration
SPECIALIZED LEAVES
Tendrils
Whiplike strands sensitive to contact
Wrap around object
Thigmotropism
Climbing vines
In some cases, tendrils are stems
Grapevine
SPECIALIZED LEAVES
Spines
Cactus spines are modified leaves
Sclerenchyma cells
Tree spines are modified stipules
Short paired spines
Thorns
Modified stems
Prickles
Outgrowth from stem epidermis
Rose and raspberries
SPECIALIZED LEAVES
Storage leaves
Water storage
Succulents
Large non-photosynthetic parenchyma cells
Large vacuoles store water
SPECIALIZED LEAVES
Storage leaves
Carbohydrate storage
Onion and other bulbs
Rapid growth early in season
SPECIALIZED LEAVES
Reproductive leaves
Miniature plants on marge of leaf
Kalanchoe
SPECIALIZED LEAVES
Floral leaves
Bracts
Colorful modified leaves at base of flowers
Poinsettia
SPECIALIZED LEAVES
Carnivorous
Over 200 species
Bogs
Nutrient deficient
Acidic
Wet
SPECIALIZED LEAVES
Pitcher Plant
Hollow leaves that often collect water
Waxy interior with downward pointing hairs
Difficult to escape
Wetting agents make it difficult to swim
Digested by enzymes
SPECIALIZED LEAVES
Sundews
Sticky fluid at the end of each hair follicle
Digestive enzymes
Hair bend inward upon contact of insect
Can distinguish difference between protein object and inedible debris
SPECIALIZED LEAVES
Venus flytrap
Native to lower NC and upper SC
Trigger hairs in foliar trap
Close on insects instead of debris
Touched a few times within seconds
Trap reopens after digestion
SPECIALIZED LEAVES
Bladderwort
Submerged bladder leaves
Trigger hairs outside a trap door
Door opens and water rushes in along with aquatic insect
AUTUMN COLOR
Chlorophyll in greatest supply
Breaks down first
Shorter day length and cooler temperatures
No longer masks other pigments
AUTUMN COLOR
Other pigments can be stored in vacuole
Anthocyanin
Red if sap is acidic
Blue if sap is basic
Betacyanins
red
ABSCISSION
Process of dropping leaves
Abscission
Evergreen plants
Gradually shed leaves
Deciduous plants
Shed leaves in winter
https://www.youtube.com/watch?v=-iHIKhKCg6E
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