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 leaflets one axillary bud Axil
Leaves
Typical leaf anatomy cuticle epidermis mesophyll palisade spongy vein bundle sheath stomata guard cells Fig adaxial surface abaxial surface
Leaf anatomy Karaba et al 2007 PNAS 104:15270 fluorescence lignin: blue chlorophyll: 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's growth leaf scars bud scale scars (from apical buds)
Meristems Fig lateral meristems vascular cambium cork cambium
vascular bundle xylem phloem fascicular cambium fasci- = bundle Primary growth
vascular bundlePrimary growth X xylem P phloem
vascular bundle interfascicular cambium xylem phloem fascicular cambium Secondary growth
vascular bundle vascular cambium xylem phloem fascicular cambium interfascicular cambium Secondary growth Year 1 Year 2
Fig 35.20
Fig X P Growth ring { late early wood wood
primary growth secondary growth (woody plants only) primary xylem and phloem secondary xylem and phloem
Dicot stemMonocot stem no secondary growth Fig (Angiosperms)
Circle dance Whirling dervishes vascular cambium
vascular cambium cork cambium cork Secondary growth
Fig { barkperiderm phloem cork cambium cork
Fig What is missing?
Root growth phloem xylem endodermis stele (vascular cylinder) Fig 35.14stele = star (e.g., 'stellar')
Q: Which term applies to the lateral meristems indicated by the arrows? (a)xylem (b)cambium (c)cork (d)cortex
Q: What is the feature surrounded by the red line? (a)leaflet (b)leaf
Q: Which is typically closer to the adaxial 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 specialised for carrying out photosynthesis. Q: How many years of growth are shown between the arrows?