Vascular plant anatomy and growth
Biol 121, Fall 2010, Tom Buckley 29 Sep 10
Leaves
leaf
leaflet
petiole
Fig 35.6
leaf: has axillary bud
leaflet: no bud
compound leaf:multiple leafletsone axillary bud
Axil
Leaves
Typical leaf anatomy
cuticle
epidermis
mesophyll
palisade
spongy
vein
bundle sheath
stomata
guard cells
Fig 35.18
adaxial surface
abaxial surface
Leaf anatomy
Karaba et al 2007 PNAS 104:15270
fluorescencelignin: bluechlorophyll: red
image by Gregory Johnson, ASU
leaf scars & bundle traces
Leaf anatomy
tendrils (climbing)
spines
succulent (water storage)
bracts (look like petals)
Modified leaves
rhizomes
stolons
bulbs
tubers
Modified stems
pneumatophores
buttress roots
Modified roots
pneumato- = air
pherein = to carry
Meristems
apical meristems in...
apical buds
axillary buds
root apices
Fig 35.11
year'sgrowth
leaf scars
bud scale scars (from apical buds)
Meristems
Fig 35.11
lateral meristems
vascular cambium
cork cambium
vascular bundle
xylemphloem
fascicularcambium
fasci- = bundle
Primary growth
vascular bundlePrimary growth
X xylem P phloem
vascular bundleinterfascicular cambium
xylemphloem
fascicularcambium
Secondary growth
vascular bundle
vascularcambium
xylemphloem
fascicularcambium
interfascicular cambiumSecondary growth
Year 1
Year 2
Fig 35.20
Fig 35.20
Fig 35.19
XP
Growth ring
{
lateearly woodwood
primary growth
secondary growth(woody plants only)
primary xylem and phloem
secondary xylem and phloem
Dicot stem Monocot stem
no secondary growth
Fig 35.17
(Angiosperms)
Circle danceWhirling dervishes
vascularcambium
vascularcambium
corkcambium
cork
Secondary growth
Fig 35.19
{bark periderm
phloemcork
cambiumcork
Fig 35.23
What is missing?
Root growth
phloem xylem
endodermis
stele (vascular cylinder)
Fig 35.14 stele = star (e.g., 'stellar')
Q: Which term applies to the lateral meristemsindicated by the arrows?
(a) xylem
(b) cambium
(c) cork
(d) cortex
Q: What is the featuresurrounded by the red line?
(a) leaflet
(b) leaf
Q: Which is typically closer to theadaxial surface -- xylem or phloem?
Q: Which is closer to the vascular cambium during winter:earlywood or latewood?
Q: True or False: A leaf is a flattened structure specialisedfor carrying out photosynthesis.
Q: How many years of growth are shown between the arrows?