Please enable JavaScript.
Coggle requires JavaScript to display documents.
Leaves (Morphology and Anatomy of Other Leaf Types (Bud Scales (primary…
Leaves
Morphology and Anatomy of Other Leaf Types
Succulent Leaves
thick & fleshy
Crassulaceae
Kalanchoe
Sedum
Portulacaceae
Portulaca
Lewisia
Aizoaceae
ice plant
Sclerophyllous Foliage Leaves
foliage must produce more sugars
limits sclerenchyma
soft
flexible
edible
sclerenchymatous leaves
hardness
resistant
animals
fungi
freezing temperatures
ultraviolet light
Leaves of Conifers
sclerophylls
thick cuticle
unpalatable chemical
thick cell walls
simple/ never compound
needles
small, flat, scale-like
Bud Scales
primary protective
small and rarely compound
petiole short or absent
tough and waxy
Spines
axillary buds
needle shaped
no mesophyll parenchyma
no vascular tissue
closely packed fibers
Tendrils
grow indefinitely
can sense contact
does not form lamina
grows around the object
Leaves with Kranz Anatomy
C₄ photosynthesis
lack palisade parenchyma
lack spongy mesophyll
prominent bundle sheaths w/ large chlorophyllous cells
adaptation to arid environments
Insect Traps
traps & digests insects
insectivory
obtain nitrogen
passive traps
incapable of movement
pitcher leaves
active traps
move during capture
sundew leaves
External Structures of Foliage Leaves
Leaf Blade (also called lamina)
light harvesting portion
simple leaf
blade of just one part
compound leaf
blade divided into several parts
leaflets=many small blades
attached to petiolule & the extension rachis
palmately compound
leaflets attached at same point
pinnately compound
leaflets attached individually to rachis
Dorsal Surface
lower side/ abaxial side
Ventral Surface
upper side/ adaxial
Petiole
stalk
holds blade out into light
abscission zone
leaf base/ usually in petiole
cells release enzymes that weaken cell walls
cuts off leaf
Sessile Leaf
no petriole
sheathing leaf base
Veins
bundles of vascular tissue
distribute water/ collect sugars
reticulate venation
netted pattern
angiosperms
eudicots
parallel ventilation
veins are side by side
monocots
Internal Structure of Foliage Leaves
Epidermis
large surface area
transpiration
water loss
guard cells/ trichomes (glandular or nonglandular) abundant
stomata
sunken into epidermal cavities
cutin
retain water/ protection
Mesophyll
palisade parenchyma (palisade mesophyll)
main photosynthetic tissue
usually one layer thick
spongy mesophyll
lower portion of leaf
loose aerenchyma
CO₂ diffusion
Vascular Tissues
midrib (midvein)
lateral veins
minor veins
release water from xylem
loading sugar into phloem
conduction/ support
conduction/ support
bundle sheath
fibers around vascular tissue
bundle sheath extension
Petiole
transition b/t stem & lamina
leaf trances
1,3,5+ vascular bundles
stipules
two small flaps
Initiation and Development of Leaves
Monocots
shoot apical meristem expansion
some apical meristem cells grow with primordium
hood-like shape
becomes a cylinder
completely encircles shoot apical meristem
Basal Angiosperms and Eudicots
produced by shoot meristem
leaf primordium
causes protrusion
leaf protoderm
differentiation
primary phloem
provascular tissue
primary xylem
leaf ground meristem
meristematic
