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Chapter 6: Leaves - Coggle Diagram
Chapter 6: Leaves
Morphology and Anatomy of Other Leaf Types
Spines
modified leaves of axillary buds
no mesophyll paren/vascular tiss
but packed fibers
deposit lignin in walls
hard/decay resist
Tendrils
grow indefinitely and sense contact
pea, cucumber, squash
Bud Scales
protect from low temp
small, rarely compound
Leaves of Conifers
sclerophylls
unpalatable chemicals
simple, few forms
perennial
evergreens
Leaves with Kranz Anatomy
metabolism C4 photosyn
lack palisade paren/spongy mesoph
prominent bundle sheaths, chlorophyllous
ring mesophyll cells radiate vascular bundle
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Sclerophyllous Foliage Leaves
soft, flexible, edible
some perennial
waxes abundant
Insect Traps
insectivory
passive traps
not mobile
pitcher leaves
active traps
move
Succulent Leaves
survive in desert habitats
thick and fleshy
External Structure of Foliage Leaves
function of
not lose a lot of water
no entry fungi, bacteria, epifoliar algae
photosynthesis
don't be delicious
Leaf Blade (lamina)
Ventral Surface
adaxial
smooth
dorsal surface
abaxial side
large veins protrude
simple leaf
has a blade of 1pt
compound leaf
blade divide into indiv. pt.
leaflets
attached by petiolule
rachis
leaf shading
petiolate
stalk hold blade into light
no petiole?
sessile leaf
monocot
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grasses, irises, lilies, agaves
typically lack petiole
sheathing leaf base instead
leaf base wrap around stem
Internal Structure of Foliage Leaves
Mesophyll
palisade parenchyma (" mesophyll)
upper surface layer cells
main photosynthetic tissue plants
ground tissues interior leaf epiderm coll
spongy mesophyll
lower portion leaf
Vascular Tissues
between palisade parenchyma and spongy mesophyll
eudicot
midrib (midvein)
lateral veins
minor veins
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release water from xylem
loading sugar into phloem
conduction
primary xylem on upper
primary phloem on lower
bundle sheath around, many fibers
leaf bundles
fuse
Epidermis
transpiration
water loss
must be reasonably water proof but translucent
must allow carbon dioxide
leaf epidermis
trichomes, hairy
some shade upper surface/deflect sun
desert plants
contain coating of cutin
retain water for no spores
stem epidermis
Petiole
massive in palms, celery, rhubarb
considered part of leaf
transition between stem-lamina
stipules
two small flaps at base
protect shoot apical meristem
photosynthesis
Initiation and Development of Leaves
Monocots
Basal Angiosperms and Eudicots
eudicots
initiated by expansion of some shoot apical meristem cells
