Petiole
- none?
- Attaches leaf blade to the stem
- Sessile
Leaf arrangement:
- Basal leaves?
- Alternate leaves?
- All leaves at the base of the stem forms rosette
- One at a node
Leaf arrangement:
- Opposite?
- Whorled?
- Pairs, members are positioned on opposite sides
- 3 or more leaves at a node
Phyllotaxy
- Arrangement of leaves and stems
Dichotomous venation
- Secondary and tertiary veins branch repeatedly in two veins (bifurcate) (ginko/waterlily)
Pinnate venation
a single primary vein with the secondary veins arising along its length like the hairs of a feather
Palmate venation
with several major veins radiating from the base of the leaf blade.
(maple leaf)
Parallel venation
Parallel veins from base of the blade (spider plant) - monocots
- Lobes are
- never have
- Large incisions
- petioles
Leaf margins:
- Serrate
- Denate
- Crenate
- Sinate
Pinnately compound
Leaves arranged off of a single stem with one on each side
Palmately compound
multiple leaves from a single node
Leaf duration:
- Most leaves
- Decidious
- Evergreen
- 1 or 2 growing seasons
- Fall at the end of growing season
- Persistent leaves
Leaf shapes:
- Ovate
- Obovate
- Elliptic
- Oblong
- Widest near base
- Widest near apex
- Widest near middle
- Hexagonal
Lotus effect
Leaf epidermis is hydrophobic or superhydrophobic
- Water repellant
- Self cleaning
- Papillae w/ a dense coating of wax
Monocot vs. dicot stomata arrangement
- Paralell and unordered
Leaves consist of:
an upper epidermis, a lower epidermis, and in between them, the mesophyll
The mesophyll is
parenchymatic and is the site of photosynthesis.
The palisade parenchyma
has narrow cells, densely packed together (with few intercellular spaces), which contain 80% of the leaf chloroplasts.
The spongy parenchyma is made of
irregularly shaped cells with numerous intercellular spaces, which contain less chloroplasts.
Large veins are accompanied
by collenchyma or fibers.
The veins have different sizes and consist of
collateral vascular bundles (xylem towards the upper epidermis and phloem towards the lower epidermis)
Undifferentiated mesophyll (many monocots)
it is a uniform chlorenchyma/spongy parenchyma
Kranz Anatomy
Inner ringle called? Contains
C4 photosynthesis
Vascular bundles surrounded by 2 rings
the inner ring, called bundle sheath cells (Bs), contain chloroplasts lacking grana
Chloroplasts = dimorphic (outer ring differs from inner)
