Please enable JavaScript.
Coggle requires JavaScript to display documents.
Ch:7 Leaves - Coggle Diagram
Ch:7 Leaves
Morphology and Anatomy of Other Leaf Types
Succulent Leaves
desert habitat
thick and fleshy leaves
few air spaces in mesophyll
photosynthesis occurs in deeply than foliage leaves
For ex:
Kalanchoe, Sedum
Sclerophyllous Foliage Leaves
Soft, flexible and edible
must produce more sugars by photosynthesis
For ex:
Lithops, Senecio rotundifolia
Leaves of Conifers
leaves are sclerophyll
has thick cuticle, thick walls on epidermis and hypodermic.
simple leaves
leaves are perennial
vascular bundles can produce new phloem but not xylem.
For ex:
Araucaria araucana,
Larix*
Bud Scales
evolutionary conversion
dormant shoot apical meristem is protected from low temperature
small and rarely compound
tougher and waxier
Spines
two types of leaves
green cactus body
moist, has water, photosynthesis
axillary buds: spines
defense mechanism
Tendrils
modified leaf
grow indefinitely
coils when encountered with object
For ex: pea plant, cucumber plant.
External Structure of Foliage leaves
leaf blade
light harvesting portion
dorsal surface has larger veins
ventral surface is usually smooth.
Petiole
holds blade out to the light.
if long narrow leaf, no petiolate. EX:
Aeonium
.
simple leaf
blase in one part only
Compound leaf
blade divided into several parts
Venations
Reticulate venation
netted pattern
found in edict and angiosperm
Parallel Venation
has one large vein
found in monocot
Internal Structure of Foliage Leaves
Epidermis
waterproof and translucent
allows entry for carbon dioxide
Transpiration
Has stomata, gaurd cells, trichomes.
Mesophyll
interior to leaf epidermis
palisade parenchyma
lower portion of cell has spongy mesophyll
Vascular tissue
between palisade parenchyma and spongy mesophyll
has mid rib and branches out as lateral veins and minor veins
bundle seats
Petiole
#
transition between stem and lamina
mesophyll is rather like cortex.
stipules
two small falls like structure
Leaves with Kranz Anatomy
C4 photosynthesis
lack palisade parenchyma and spongy mesophyll
Insect Traps
Insectivore
plants growing in nitrates and ammonia poor habitat
Two traps
Active
moves during capture
For Ex: leaves of sundew
Drosera
Passive
does not move during capture
For ex:
Nepenthes, Darlingtonia
Initiation and development of leaves
Basal Angoisperm and eudicots
#
leaves produced from shoot apical meristem
leaf primordium
dormant in perennial plants
Monocots
#
developed from shoot meristem
primordium surrounds the shoot apical meristem
protoxylem and protophloem is stretched.
involved in photosynthesis
provide protection, support, storage, nitrogen procurement.
