Transcript Botany 22.1 Notes

3 Divisions of Non-vascular
Non-seed plants

Scientific Names

Common Names

Hepaticophyta

Liverworts

Anthocerophyta

Hornworts

Bryophyta

Mosses
Evolution of Plants – We’ll start at the beginning with the non-vascular plants.
Why move to land?
More CO2
 More sunlight
 No pathogens (diseases)
 No predators (no herbivores – they
didn’t exist yet!)
 Nutrient rich soil

Common characteristics among nonvascular non-seed plants
Small
 No true organs (stems, roots, leaves)
because they have no vascular tissue
 Stomata (pores where H2O is lost)
are always open
 Must have H2O for reproduction
 The gametophyte generation is
dominant

Hepaticophyta
Liverworts
 Ancestors of all
plants
 May be thallose
(lobed leaves) or
leafy (thin
leaves
 Rhizoids anchor
them to the
ground.
Liverwort sporophyte
Liverwort sporophyte growing out of the gametophyte
Gemmae on a thallose liverwort– a means of
asexual reproduction.
Leafy liverwort
Bryophyta
Mosses
The most diverse
division of the 3.
Have elongated cells
to conduct H2O
Rhizoids to anchor
Some can live in
deserts, others
submerged in H2O
Reproductive life cycle of Mosses
Moss sporophytes growing out of the
moss gametophyte
Moss sporophyte
Another moss
Cutting peat in a peat bog
The Bog Man
This man died
approximately 2000 years
ago and was preserved in
a peat bog.
Because the bog is
extremely acidic and
contains very little oxygen it
prevents the
microorganisms that cause
decay from developing.
Anthocerophyta
Hornworts
 Cells
usually contain one
chloroplast
 Many work together with nitrogen
fixing bacteria
 Sporophyte is similar to vascular
plants