Please enable JavaScript.
Coggle requires JavaScript to display documents.
Vascular Plants Without Seeds (Equisetophytes (True monopodial growth…
Vascular Plants Without Seeds
Evolution Theories
Transformation Theory
Gametophyte and Sporophyte became larger and more complex
Interpolation Theory
sporophytes were made by a zygote germinating mitotically rather than meiotically
Early Vascular plants
Rhyniophytes
simple upright stems
equal dichotomous branching
simple xylem composed of tracheas
sporangium open to release spores
Ferns
about 300 living species
found in any habitat
no vascular system, epidermis when germinated
Two types of sporangia
Eusporangia
several cells divide into multi-level disk
Lepiosporangia
singles cell protrudes out
Xylem Structure
Protostele
center of mass of xylem; No pith
Endarch protostele
xylem in the center, metaxylem in outer mass
Exarch protostele
metaxylem in middle, xylem mass on edges
Zosterophyllophytes
3 distinct traits
sporangium are open and transverse
exarch protostele
sporangia are lateral
Lines of evolution
Lycophytes
Called microphylis for clarity
Lateral sporangia
exarch protostele
zosterophyllum ancestor
has vascular cambium and secondary growth
Heterospory
Spores in cones called strobili
Trimerophytes
resemble Rhyniophytes
Pseudomonopodial branching
one single main trunk
over shading among leaves
Origin of Megaphylis
leaves on gametophytes of non vascular plants
microphylls of zosterophyllophytes
distinct homoplastic structure
Equisetophytes
all herbs without secondary growth
stems have piths
sporangia located under "umbrella" in bundles of 5-10
True monopodial growth
Main trunk, lateral branches, true leave and roots
