Please enable JavaScript.
Coggle requires JavaScript to display documents.
seed plants 1: without flowers (division coniferophyta: conifers # (pines…
seed plants 1: without flowers
division progymnospermophyta: progymnosperms
aneurophyttales
vary from shrubs to large trees
proteokalon, tetraxylopteris, triloboxylon
have vascular cambium and secondary growth
resembled trimerophytes
little webbing between ultimate branches
archaeopteridales
#
trees up to 8.4 m tall
stems contain siphonostele, pith surrounded by primary xylem
fronds resembled fern leaves
reproduction- heterosporous
evolution of seeds
megasporangium surrounded by tissue called an integument
large micropyle- hole that permitted sperm cells to swim to the egg
pollen chamber- place where microspores settles
some gave rise to conifers, cycads, and other gymnosperms
develops megaphyllous leaves
division pteridospermophyta: seed ferns
gave rise to cyadophytes
3 divisions
pteridospermophyta
cyadophyta
extant species
cycadeoidophyta
earliest seed ferns appeared in upper deonian period
thought to evolved from aneurophytales
a lot of similarities to angiosperms and gymnosperms
vascular camium that produced xylem and phloem
vascular bundles surrounding the pith
division coniferophyta: conifers
#
never vines, herbs, or annuals
simple venation of leaves
leaves contain transfusion tissue
pines (conifer) has 2 types of shoots
long shoots on axils
short shoots that produce needle like leaves
produce pollen cones and seed cones
pollen cones- simple cones
seed cones- compound cones
ovuliferous scale
fused megasporophylls laterally
reproduction
first cells elongate as a suspensor
other cells called proembryo develop into the embryo
division of cycodophyta: cycads
cyad foliage leaves do not bear ovules
produce seed cones and pollen cones
seed cones are large
dioecious
division of cycadeoidophyta: cycadeoids
never considered distinct from cycads
individual cones contain microsporophylls and megasporophylls
microsporophylls located below megasporophylls
division of ginkgophyta: maidenhair tree
#
division contains a single living species
wood is like that of conifers
lacks vessel and axial parenchyma
broad leaves
dichotomously branched
gingkos have both shoot and long shoots
dioecious
division gnetophyta
3 groups
enigmatic plants
ephedra
tough shrubs and bushes
resemble dicots
welwitshia
contains only 2 leaves
grow indeterminately from basal meristems
mostly vines or small shrubs
reproduction- gymnospermous
some characteristics resembled ferns
both produce seed and pollen cones
similar to conifers have short and long shoots
this is an image of a gingko tree
this is an image of a conifer and its cones
this is an image of a gnetophyte
