2. Outline of Classification followed
in the Book
Divisions
Cycadophyta
Ginkgophyta
Coniferophyta
Gnetophyta
3. Cycadophyta
Cycads are vascular, seed
plants that are palm-like and
are called Sago Palms. The
leaves are found in a cluster
at the tops of the trunks.
Cycads were first to show
“true secondary growth”
along plant’s evolutionary
history.
5. Ginkgophyta
Ginkgophyta is a plant
division of “non-flowering
trees”.
Habitat:
USA, Canada, China,
India, Japan, South Korea,
Singapore, Taiwan, Africa,
New Zealand, and many other
countries…..
7. Coniferophyta
It is a largest phylum of “gymnosperms”.
This is a conspicuous group of woody plants
commonly known as the "conifers". The
members of this group produce ovules that
mature into seeds. These ovules and seeds
are found on the upper surfaces of scale
structures which often are clustered into
"cones". The Coniferophytes are considered
"gymnosperms" (as are the Ginkgophytes)
due to the fact that the seeds are exposed in
the cone scales rather than being enclosed
within an ovary as in the Angiosperms
(flowering plants). All conifers are woody
plants and many form very large trees. Most
conifers are evergreen,
however, Metasequoia glyptostroboides (see
below) is one locally cultivated, non-native
example of a conifer that is deciduous
8. Classes
Cordaitopsida
Comprises of extinct plants
and represented by fossils.
Coniferopsida
50 genera + 550 species.
Trees such as Tsuga(hemlock),
Abies(fir), Picea(spruce),
Junipers(juniper, red cedar),
Sequoiadendron(sierra
redwood) etc.
Taxopsida
Female strobilus is absent
& ovules develop at the ends of
short lateral branches.
Taxus & Torreya are
representative genera of class.