Please enable JavaScript.
Coggle requires JavaScript to display documents.
Chapter 22: Seed Plants I: Seed Plants Without Flowers (“Gymnosperms”),…
Chapter 22: Seed Plants I: Seed Plants Without Flowers (“Gymnosperms”)
Division Coniferophyta: Conifers
diverse
trees
leaves = simple needles or scales
usually perrenial
venation
simple veins
transfusion tissue
#
transfusion parenchyma
cork cambium - bark
shoot
long
short
occur on axils of long
long needle leaves
tiny papery leaves
pines
pollen cones
simple cones
single short unbranched axis
bears microsporophylls
meiosis
endosporially develop
four cells
seed cones
compound cones
shoot w/ axillary buds
bears leaves called
cone
bracts
megasporophylls
ovuliferous scale
megaspore
1 more item...
suspensor
elongate
proembryo
embryo
grow act as nutritive tissue
Division Pteridospermophyta: Seed Ferns
earliest seed ferns
woody plant w/ fern foliage
bore seeds
Pteridosperms
thick cortex
radial plates
secretory ducts
all extinct
Division Cycadophyta: Cycads
stout trunks
pinnately compound leaves
most = short
no ovules
seed cones & pollen cones
dioecious
tropical w/ unusual distribution
no cold
Division Progymnospermophyta: Progymnosperms
Aneurophytales
shrubs - large trees
vascular cambium & secondary growth
primary xylem stems -
protostele
Archaeopteridales
abundant wooded trees w/ secondary phloem
stems -
siphonostele
pith surrounded by ring of primary xylem bundles
reproduction-
heterosporous
no seeds
Evolution of Seeds
earliest known progymnosperm
chauleria
megasporangium
3 aborted cells
viable megaspore
surrounded by layer of tissue-
integument
pollen chamber
holding area for microspores
extinct
megaphyllous leaves
evolution of vascular cambium
no seeds
no ovule
Division Cycadeoidophyta: Cycadeoids
#
all extinct
vegetative features
differ from cycads
stomatal complexes & in leaf trace organization
Division Gnetophyta
Enigmatic Plants
Gnetum
~30 species
vines/small shrubs
Ephedra
~40 species
tough shrubs & bushes
Welwitschia mirabilis
only 1
short wide stem w/ only 2 leaves
Division Ginkgophyta: Maidenhair Tree
single species
lacks vessels & axial parenchyma
males - yellow leaves
females-putrid odor
Lignophytes
Spermatophytes
Gymnosperms
Angiosperms
flowering plants
naked ovules
“ seed plant” originated
monophyletic “woody plant”
#
wood
manoxylic
soft, spongy , parenchymatous wood
large compound leaves
radially symmetrical seeds
pycnoxylic
hard, strong, little parenchyma wood
small simple leaves
flattened seeds
vascular cambia
similar to cycads
cell types=complex facilitating transfer of materials
woody
