Million years of evolution:
Angiosperm
Cooksonia
Angiosperms and plant anatomy
Practical # 3Mid-term evaluations (lab 6 of 10)LectureScavenger HuntTurn in cladistics worksheet p 123-4
Next week:Last lab practical
400mya
• http://www.johnkyrk.com/evolution.html
Paleo plant and insect interactions
Older Younger
Insects and plants evolved together
The unique character of angiosperms is that the ovules are
completely enclosed in a carpel
1. gametophytes only a few cells
2. immotile sperm- carried to ovule by pollen tube
3. No “spores” because reduced gametophyte
Controversy about its floral morphology interpretation
Extinct
http://www.pbs.org/wgbh/nova/flower/anat-flash.html
http://www.pbs.org/wgbh/nova/flower/
Knowing the flower anatomy…let’s review the fossil record of earliest angiosperms
keep in mind:
• To date, the origin of the angiosperms remains controversial
• No consensus about the ancestral relative
• Molecular evidence suggest a Jurassic origin (>150 Ma), but the oldest fossils is early Cretaceous (~125 Ma)
MORE INFO: http://www.mobot.org/mobot/research/apweb/welcome.html
UF grad student found this one!
Extinct
Many early flowers arerelated to living
Angiosperms families
Pollination of ‘primitive’ flowers
Flowers adapted for pollination by "smart" insects
Insects can see uv light
Insects can see uv light
What pollinates these?
Wind-pollinated flowerssecondarily derived in Angiosperms
-- flowers are green, small, and often lack petals. Wind pollinated flowers of deciduous trees species open in early spring –
why?
Pick the Pollinator
http://www.pbs.org/wgbh/nova/flower/pollinator.html
Plant parts
Take a look…
Primitive vs Derived characters
• http://botany.csdl.tamu.edu/FLORA/tfplab/primder.htm
Fruit and seed dispersal
Don’t forget…
Also: ichthyochory
?
What disperses these?
Pleistocene extinction
Gomphothere
Late Pleistocene Extinctions
– 13,000 years ago, N & S America
“Re-wilding of N. America?”
Angiosperms often used for medicine – why?
Preparing ayahuasca
3 clades
A. Monocotyledones (monocots)
B. Magnoliids
C. Eudicotyledones (dicots)
ANGIOSPERMS
Generalized distinguishing characteristics:
MONOCOTSone cotyledon
parallel venation
scattered vascular bundles
floral parts in 3's
adventitious roots
pollen monosulcate
EUDICOTStwo cotyledons
reticulate venation
vascular bundles in rings
floral parts in 4's or 5's
taproots common
pollen tricolpate
MAGNOLIIDStwo cotyledons
reticulate venation
vascular bundles in rings
parts in 3's or numerous
taproots common
pollen monosulcate
A comparison of monocots and dicots -- know this for lab practical
Lab exercise – can you tell them apart?
All flesh is grass” -- Isaiah
Grasses evolved directly with mammals
MONOCOTS
Bamboo
Pineapple Onion
Banana
Palms!
Harvesting palm hearts
‘ivory palm’
Coconuts
Bactris gasipaes
‘peach palm’
One apical bud!!
Monocot stem -- vascular bundles
xylem
phloem
Dicot stem
Dicots have secondary growth
Xylem and phloem in rings
Which tree has a better chance to
live?
Monocot (palm)Dicot
Annual growth rings?
Illegal mahagony logging
Dicot stems
We eat many, many dicot fruitsExamples?
Theobroma cacao
In common?
Chinese kale
cabbage
Kale
Collard greens
Califlower
Brussel sprouts
Broccoli
Kohlrabi
Brassica oleracea
Chinese kale
cabbage
Kale
Collard greens
Califlower
Brussel sprouts
Broccoli
Kohlrabi
‘wild mustard’
Brassica oleracea
‘wild mustard’
Vavilov Centers of origin
for crop plants
http://www.hort.purdue.edu/newcrop/history/lecture05/lec05.html
Anatomy study slides
The life cycle of an angiosperm
Angiosperm life cycle
Plant morphology/anatomy
Primary vs. secondary growthA. Apical meristems - primary growth
B. Cambium (vascular or cork) - secondary growth
C. In lab -. Apical meristems1. Coleus - stem tip (no. 3) - herbaceous dicot
2. Zea - root longitudinal section (no. 4) - monocot
Seed anatomy Scan
StemsA. Anatomy
1.parenchyma (pith) 6. xylem2.sclerenchyma 7. phloem3.epidermis 8. vascular cambium4.cork & cork cambium 9. meristem5.cortex 10. node
B. In lab:1.Helianthus - stem (no. 5) - herbaceous dicot2.Tilia - stem cross sections (no. 6) - woody dicot3.Zea - stem cross section (no. 7)
Morphology of a flowering plant
Morphology of a winter twig
Anatomy of a tree trunk
Organization of primary tissues in young stems
Leaves
A. Anatomy1. palisade mesophyll 5.
stomata
2. spongy mesophyll 6. xylem
3. epidermis 7. phloem
4. cuticle
B. In lab:1. Ligustrum - leaf section (no. 8)
Leaf anatomy
Simple versus compound leaves
a. Simpleb. Compound
i. palmateii. pinnate
RootsA. Anatomy
1.epidermis 5. casparian strip2.cortex 6. pericycle3.stele 7. xylem4.endodermis 8. phloem
B. In lab:1.Ranunculus - root (no. 9)2.Salix - branch root (no. 10)3.radish root hairs4.sweet potato demo - storage root5.carrot - root stores sugars
Primary growth of a root
Organization of primary tissues in young roots
The formation of lateral roots
Root hairs of a radish seedling
Storage organs
A. white potato demo - modified stem
B. green onion demo - leaves modified for storage
C. celery - leaf petiole modified
D. sweet potato demo - storage root
E. carrot - root stores sugars
Principal Biological Concepts this lab:
A. Angiosperms as dominant plant taxon.B. Ovules enclosed within two integuments and a carpel
wall.C. Structure and function of flowers, and importance of
pollinators.D. Carpel wall may ripen as pericarp = fruit.E. Monocots versus dicotsF. Double fertilization.G. Plant tissues.H. Primary and secondary growth.I. Structure and function of shoots, roots, and leaves.
To study for next lab practical
• Moncots vs dicots• Flower parts• Leaf structures• Stem structures, xylem vs phloem,
monocots vs dicot vasculature• Root tissues & functions• Xylem vs phloem
Complete Plant Cladistic Exercise
A. Follow directions in Plant Cladistics data sheet (pp. 123-124).
B. Complete the cladogram and hand in before you leave.