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LEAVES :recycle: (Morphology and anatomy of other leaf types (leafs of…
LEAVES :recycle:
Morphology and anatomy of other leaf types
succulent leaves
numerous adaptations
permits plants to survive in desert habitiats
some leaves are cylindrical
optimal to volume shape
thick and fleshy
reduces the surface to volume ratio
favors water conservation
inside leaf
mesophyll
contains few air spaces
reduces internal evaporative surface area
makes mesophyll transparent
sclerophyllous foliage leaves
leaves have evolved which are perennial
existing on plant for two or more years
with this extended lifetime
leaves are feasible
hardness makes them resistant
fungi
freezing temperature
animals
ultra violet light
sclerenchyma
a layer below the epidermis and bundle sheaths
must produce more sugars by photosynthesis
leafs of conifers
thick cells walls
epidermis
hypodermis
simple
needles
short or long
occur in all pine, firs, and spruces
thick cuticle
small and flat scale like leaves
from a shield stems
junipers
thuja
cypresses
leafs of sclerophylls
broad scales
hold away from stem
podocarpus
aramcaria
agathis
mostly perennial
unpalatable chemicals
shed leaves each autumn
tax odium
metasequoia
larix
spines
have no blade
needle shaped
have a distinct structure related to function
no mesophyll parenchyma or vascular tissue present
instead consists closely packed tissues
fibers mature
deposit lignin in walls
resistant to decay
modified leaves of axillary buds
leaves with kranz anatomy
lack spongy mesophyll
kranz anatomy
adapts C4 plants
to arid environments
these leaves lack palisade parenchyma
have bundle sheaths
composed of large chlorophylous cells
surrounding each sheath
ring of mesophyll cells
appear to radiate from vascular bundle
tendrils
grow indefinitely
contain cells that are capable of sensing constant with an object
another from of modified leaves
when is touches something
the side facing the object
stops growing
the other side
continues to elongate
causes rendrait to coil around object
for support
insect traps
by digesting insects
plants obtain nitrogen
needed
from amino acids and nucleotides
has evolved on plants that grow in habitats poor in nitrate and ammonia
epidermis
digestive region
lamina
is tubular not flat
secretes a watery digestive fluid
most known
nepenthes darlingnota
similar to foliage leaves
is thin
capable of photosynthesizing
parenchymatous
numerous stomata and vascular bundles
has mesophyll
arenchyma
sarracenia
numerous trichomes
insects lead to death
Internal Structure of foliage leaves
epidermis
waterproof but transparent
transpiration
leaf epidermis
cutin
retains water
make digestion difficult
trichomes
provide shade on upper surface
deflect excessive sunlight
in lower surface
slow water loss stomata
prevent rapid air
hairy
stomata is greater on the lower epidermis
leaf and stem epidermis are basically similar
mesophyll
upper layer of cells
palisade parenchyma
main photosynthetic tissue of most plants
also called the palisade mesophyll
palisade cells
seperated
cell has most surface exposed to intercellular spaces
CO2 dissolves into cytoplasm slowly
lower portion of leaf
spongy mesophyll
occurs in center of the leaf
between spongy mesophyll & palisade chlorophyll
vascular tissue
midvein
lateral veins emerge
then branch out to minor veins
release water from xylem
loads sugars into phloem
around vascular tissue
many fibers
arranged as a sheath
bundle sheath
petiole
petiole mesophyll
somewhat compact
many vascular bundles
leaf traces
arranged in many ways
in many species
petiole bears
two small flaps stipules
to protect the shoot of the apical meristem
Initiation & development of leaves
basal angiosperms and eudicots
base of meristem
leaf primordial
becomes taller than shoot apical meristem
primordium consists of leaf protoderm
extend upward into narrow cone
gets thicker
establishing the bulk midrib
row of cells from outward
lamina
monocots
some monocots
lamina becomes broad
more apical meristem
primordial is a cylinder
completely or almost encircles the shoot apical meristem
tubular portion grows
inner surface
adaxial epidermis
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cheating leaf base
the outer space of the tube
abaxial epidermis
initiated by expansion apical meristem cells
External Structure of Foliage Leaves
shoot stem
leaf
support
tendrils
storage
fleshly leaves of bulbs
flat large green
protection
bud
scales
spines
flat and thin
chlorophyll rich chlorenchyma
photosynthesis
to absorb light and CO2
nitrogen procurement
trapping and digesting insects
bundles vascular tissue
veins
simultaneously collect sugars
that are produced from photosynthesis
monocots
few obvious inner connections
parallel variation
distribute water
from stem
into the leaf
basal angiosperms and eudicots
netted pattern
reticulate venation
foliage leaves
most familiar
thin, flat, addable to photosynthesize
leaf blade
holds blade out of sunlight
petiole
leaf base
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long thin flexible
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lamina
small, very long, and narrow
no petiole
leaf wraps around stem
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sessile leaf
compounded leaf
better adapted than the single ones
blade divided into several parts
tearing prevented
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upper side
ventral surface
adaxial side
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simple leaf
largest
Victoria water lily
blade of one part
may tear with wind
blades lower side
dorsal surface
backbones
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absorb CO2
convert to carbohydrate
stems
cylindrical stem
treachery elements
fibers
die to be functional
elevate leaves
