Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 22 Seed Plants I: Seed Plants Without Flow... (Division…
Chapter 22 Seed Plants I: Seed Plants Without Flow...
Concepts :check:
Cambium
lignophytes
plant that give rise to monophyletic group of woody plants
spermatophytes.
seeds originated establishing seed plants.
Gymnosperms
plants with naked ovules.
#
example; pine cones.
Angiosperms.
flowering plants
carples
Division Progymnospermophyta: Progymnosperms
:red_cross:
A third group to evolve from trimerophytes
Aneurophytales.
primary xylem in stems was a protostele
vary in stature
all had a vascular cambium and secondary growth
contains the more relictual progymnosperms
trunks upto 1.5m in diameter and 12 m tall.
Archaeopteridales
abundant wood with secondary phloem
reproduction
heterosporous
more derived progymnosperm
"fronds" were planted branch systems
ring of primary xylem bundles
leaflets were serially arranged simple leaves
Evolution of seeds.
#
four types of pollen became common common after Upper Devonian Period
earliest known species
Chauleria
from Middle Devonian Period
microphyla
some fossils help us understand the early stages
hole in integument
permitted sperm cells to swim to the egg
pollen chamber
holding area for microspores
evolved into pollen grains
megasporangia
evolved into ovules with integuments
Division Pteridospermophyta: Seed Ferns
:<3:
ring of vascular bundles surrounding pith
any woody plant with fern-like foliage
thought to have evolved from the Anueophytales
wood was manoxylic
leaves similar to true ferns
foliage leaves bore seeds
(unlike seed ferns)
large
compound
planar.
(unlike seed ferns)
inner cortex
thick cortex around stem
Conifers
Division Coniferophyta: Conifers
simple venation of leaves
two types of shoot
short shoots
long shoots
leaf veins contain
endodermis
transfusion tissue
cones
pollen cones
simple
seed cones
compound
example
never herbs, vines, or annuals
microscopic axillary bud
its megasporophylls are fused to form ovuliferous scale
moderate to gigantic size
Division Cycadophyta: Cycad
:forbidden:
trunk is covered with bark
produce seed and pollen cones
short (less than 1-2 cm tall)
cycad foilage leaves do not bear ovules.
much larger group with more species.
Highly prized ornamental in the warmest parts of the united states.
Division Cycadeoiphyta: Cycadeoids
:warning:
both cycadeoids and cycads
each ovule had a stalk
had vegetative features
contained microsporophylls and megasporophylls
megasporangium was surrounded by an integument
each microsporophyll
was cup shaped
contained numerous sporangia
Division Ginkophyta: Maidenhair Tree
:!!:
contains a single living species
looks much like a large dicot tree
lacks vessels and axial parenchyma
popular ornamental
reproduction is dioecious
wood like conifers
#
Division Gnetophyta
:star:
contains three groups of enigmatic plants
Ephedra
about 40 species
touch shrubs and brushes
Gnetum
leaves similar to those of dicots
30 species
mostly vines or small shrubs
Welwitschia Mirabilis
short, wide stem
exists only in deserts of South Africa or in cultivation
only species in the genus
only two leaves
