1. Rosette cellulose-synthesizing complexes Found only in land plants and charophycean green algae
Figure 29.2 Rosette cellulose-synthesizing complexes
30 nm

2. Three Clades are candidates for Plant Kingdom
Red algae
ANCESTRAL
ALGA
Chlorophytes
Viridiplantae
Charophytes
Figure 29.4 Three possible “plant” kingdoms
Streptophyta
Embryophytes
Plantae

3. Alternation of generations = Derived traits of land plants
Land Plants Life Cycle
Gamete from
another plant
Gametophyte
(n)
Mitosis
Mitosis n n n n
Spore
Gamete
MEIOSIS
FERTILIZATION
Zygote 2n
Figure 29.5 Derived traits of land plants
Mitosis
Sporophyte
(2n)
Alternation of generations = Derived traits of land plants

4. Derived Traits of Land Plants Multicellular Dependent Embryos
Maternal tissue
Figure 29.5 Derived traits of land plants
Wall ingrowths
10 µm
Placental transfer cell
(outlined in blue)
Embryo (LM) and placental transfer cell (TEM)
of Marchantia (a liverwort)

5. Sporophyte 2n Gametophyte n Spores Sporangium Longitudinal section of
Derived Traits of Land Plants: Walled Spores Produced in Sporangia:
Spores
Sporangium
Longitudinal section of
Sphagnum sporangium (LM)
Figure 29.5 Derived traits of land plants
Sporophyte 2n
Gametophyte n
Sporophytes and sporangia of Sphagnum (a moss)

6. Archegonia and Antheridia of Marchantia (a liverwort)
Derived Traits of Land Plants: Multicellular Gametangia - ‘sex organs’
Archegonium
with egg
Female gametophyte
Antheridium
with sperm
Figure 29.5 Derived traits of land plants
Male
gametophyte
Archegonia and Antheridia of Marchantia (a liverwort)

7. Derived Traits of Land Plants
Apical Meristems - Allow for Growth in Length throughout Plant’s Lifetime.
Apical
meristem
of shoot
Developing
leaves
Apical meristems
Figure 29.5 Derived traits of land plants
Apical meristem
of root
Shoot
Root
100 µm
100 µm
Derived Traits of Land Plants

8. NonVascular and Vascular Plants
Table 29.1

9. Highlights of Plant Evolution1
Origin of land plants (about 475 mya) 2
Origin of vascular plants (about 420 mya) 3
Origin of extant seed plants (about 305 mya)
Liverworts
Nonvascular
plants
(bryophytes)
Land plants
ANCES-
TRAL
GREEN
ALGA 1
Hornworts
Mosses
Lycophytes (club mosses,
spike mosses, quillworts)
Seedless
vascular
plants 2
Vascular plants
Pterophytes (ferns,
horsetails, whisk ferns)
Figure 29.7 Highlights of plant evolution
Gymnosperms 3
Seed plants
Angiosperms
500
450
400
350
300 50
Millions of years ago (mya)

10. Life Cycle of a Bryophyte > Moss Gametophyte is the Dominant Generation
Raindrop
Sperm
“Bud”
Antheridia
Male
gametophyte
(n)
Key
Haploid (n)
Protonema
(n)
Diploid (2n)
“Bud”
Egg
Spores
Gametophore
Archegonia
Spore
dispersal
Female
gametophyte (n)
Rhizoid
Peristome
Sporangium
FERTILIZATION
Figure 29.8 The life cycle of a moss
MEIOSIS
(within archegonium)
Seta
Zygote
(2n)
Capsule
(sporangium)
Mature
sporophytes
Foot
Embryo
Archegonium
Young
sporophyte
(2n)
2 mm
Capsule with
peristome (SEM)
Female
gametophytes

11. Bryophyte Structures Sporophyte Gametophore of female gametophyte
Thallus
Sporophyte
Foot
Seta
Figure 29.9 Bryophyte diversity
Capsule
(sporangium)
Marchantia polymorpha,
a “thalloid” liverwort
500 µm
Marchantia sporophyte (LM)

12. Annual nitrogen loss (kg/ha)
Bryophytes / Moss may help retain Nitrogen in the soil, an Ecological Advantage
RESULTS 6 5 4
Annual nitrogen loss
(kg/ha) 3 2
Figure Can bryophytes reduce the rate at which key nutrients are lost from soils? 1
With moss
Without moss

13. Sphagnum, or peat moss: economic and archaeological significance
(a) Peat being harvested from a peat bog.
Figure Sphagnum, or peat moss: a bryophyte with economic, ecological, and archaeological significance
(b) “Tollund Man,” a bog mummy: The acidic, oxygen poor conditions
can preserve bodies.

14. Life Cycle of a Seedless Vascular Plant - Fern Dominant Sporophyte
Key
Haploid (n)
Diploid (2n)
Spore
(n)
Antheridium
Young
gametophyte
Spore
dispersal
MEIOSIS
Sporangium
Mature
gametophyte
(n)
Sperm
Archegonium
Egg
Mature
sporophyte
(2n)
Sporangium
New
sporophyte
Zygote
(2n)
FERTILIZATION
Sorus
Figure The life cycle of a fern
Gametophyte
Fiddlehead

15. Hypotheses for Evolution of Leaves
Overtopping
growth
Megaphyll
Vascular tissue
Sporangia
Microphyll
Other stems
become re-
duced and
flattened.
Webbing
develops.
Figure Hypotheses for the evolution of leaves
(a) Microphylls - single veined leaves
(b) Megaphylls - branching leaf veins

16. Homosporous spore production
Typically a
bisexual
gametophyte
Eggs
Sporangium
on sporophyll
Single
type of spore
Sperm
Heterosporous spore production
Megasporangium
on megasporophyll
Female
gametophyte
Megaspore
Eggs
Microsporangium
on microsporophyll
Microspore
Male
gametophyte
Sperm

17. Seedless Vascular Plants
Lycophytes (Phylum Lycophyta)
2.5 cm
Isoetes
gunnii,
a quillwort
Strobili
(clusters of
sporophylls)
Selaginella apoda,
a spike moss
Figure Seedless vascular plant diversity
1 cm
Diphasiastrum tristachyum, a club moss

18. Seedless Vascular Plants
Pterophytes (Phylum Pterophyta)
Athyrium
filix-femina,
lady fern
Equisetum
arvense,
field
horsetail
Psilotum
nudum,
a whisk
fern
Vegetative stem
Strobilus on
fertile stem
Figure Seedless vascular plant diversity
25 cm
1.5 cm
2.5 cm

19. Artist’s depiction of a Carboniferous forest based on fossil evidence
Figure Artist’s conception of a Carboniferous forest based on fossil evidence

20. Derived Traits of Plants
Apical meristem
of shoot
Developing
leaves
Gametophyte
Mitosis
Mitosis n n n n
Spore
Gamete
MEIOSIS
FERTILIZATION 2n
Zygote
Mitosis
Haploid
Sporophyte
Diploid 1
Alternation of generations 2
Apical meristems
Archegonium
with egg
Antheridium
with sperm
Sporangium
Spores 3
Multicellular gametangia 4
Walled spores in sporangia

21. You should now be able to:
Describe four shared characteristics and four distinct characteristics between charophytes and land plants.
Diagram and label the life cycle of a bryophyte
Explain why most bryophytes grow close to the ground and are restricted to periodically moist environments.
Describe three traits that characterize modern vascular plants and explain how these traits have contributed to success on land.

22. Explain how vascular plants differ from bryophytes.
Distinguish between the following pairs of terms: homosporous and heterosporous.
Diagram and label the life cycle of a seedless vascular plant.