Please enable JavaScript.
Coggle requires JavaScript to display documents.
CHAPTER 21: VASCULAR PLANTS WITHOUT SEEDS - Coggle Diagram
CHAPTER 21: VASCULAR PLANTS WITHOUT SEEDS
Concepts
dibiontic life cycle
multicellular gametophyte
multicellular sporophyte
monobiontic
one multicellular generation
interpolation hypothesis
small sporophyte came into existence
zygote divided mitotically instead of meiotically
sporophyte generation evolved
transformation theory
dibiontic life cycle originated
gametophyte and sporophyte became larger, more complex, and vascularized
alteration of isomorphic generations
The Microphyll Line of Evolution: Lycophytes
resemble zosterophllophytes
#
lateral sporangia
exarch protosteles
Morphology
large vascularized enations
microphylls
true roots
anchor
absorb
vascular cambium
secondary growth
no longitudinal division
no new fusiform initials
limited radial growth
Heterospory
sporangia clustered together
cones or strobili
heterosporous
microspores
microgametophytes
megaspores
megagametophytes
existed within wall of megaspore
similar to ovules and seeds
precondition for evolution of seeds
Extant Genera
Lycopodium
ground pine or club moss
herbs with rhizomes and true roots
spirally arranged microphylls
no secondary growth
homosporous
Selaginella
resurrection plant
heterosporous
ligule
small flap of tissue
Isoetes
quillworts
heterosporous
microphylls with ligules
small amount of secondary growth
CAM photosynthesis
The Megaphyll Line of Evolution: Euphyllophytes
Trimerophytes
resemble rhyniophytes
#
terminal sporangia
dehisced laterally
homospory
dichotomous branching
endarch protostele
overtopping
unequal branching
one stem was more vigorous
pseudomonopodial branching
Pertica
single main trunk
evolved into ancestors of ferns and seed plants
Origin of Megaphylls (Euphylls)
analogous structures called leaves
leaves on gameophytes of nonvascular plants
enations/microphylls of zosterophyllophytes and lycophytes
megaphylls
leaves evolved from branch systems
telome theory
ultimate twigs
telomes
planation
webbing
monophyletic clade
euphyllophytes
Monilophytes
synapomorphies
roots have exarch xylem
have megaphylls
large inversion in single-copy region of plastid DNA
sister clades
monilophytes
ferns
fern allies
lignophytes
woody plants
Equisetophytes
horsetails or scouring rushes
herbs without secondary growth
whorl of leaves at nodes
small megaphylls
stems have pith
siphonsteles
endarch
canals
umbrella shaped sporangiophore
form strobilus
no new fusiform initials
Ferns
leptosporangiate ferns
sporophyte
single axis
true roots
megaphyllous leaves
endarch siphonostele
leaf trace
leaf gap
leaves
palisade and spongy layers
compound
distinct apical cell
tightly coiled young leaf
fiddlehead
leaf veins branch dichotomously
underside of leaf
sori
clusters of sporangia
mostly homosporous
heart shaped gametophyte
bear antheridia and archegonia
Eusporangia and Leptosporangia
eusporangium
small, multilayered plate of cells
large sporangium
many spores
several surface cells undergo periclinal divisions
leptosporangia
single cell divides periclinally
small, outward protrusion
small sporagnium
few spores
Psilotum
and
Tmesipteris
simplest of all living vascular plants
Psilotum
similar to
Rhynia
and
Aglaophton
highly simplified ferns
epidermis, cortex, protostele
heterotrophic gametophytes
contains vascular tissue
The Term "Vascular Cryptogams"
contain vascular tissue
lack seeds
Early Vascular Plants
Rhyniophytes
Cooksonia
upright stems with no leaves
equal dichotomous branching
xylem
tracheids with annular secondary walls
ends of branches
multicellular masses of sporangenous tissue
homosporous
endarch protostele
Zosterophyllophytes
small herbs without secondary growth
lateral spotangia
not terminal
sporangia open transversely along top edge
exarch protostele
enations
increase photosynthetic surface area
Xylem Structure of Early Vascular Plants
solid mass of xylem with no pith
protostele
endarch protostele
protoxylem in center
metaxylem on outer edge
exarch protostele
metaxylem located in center
protoxylem on edge as groups
pith present in center
siphonostele
ferns and seed plants
