1. 29-30: Kingdom Plantae What constitutes a plant?
What are the evolutionary trends in plants?
What are the reproductive trends in plants?

2. The Netherlands

3. What constitutes a plant?
Plants are:
Multicellular
Eukaryotes
Photosynthetic autotrophs
Algae may also have these characteristics.
Plants appear to have developed from algae.
Other features that plants and algae have in common:
Presence of chrolophyll b as an accessory pigment
Cellulose cell walls
Starch as storage product of surplus carbohydrates
Plants occur both on land and in water. Algae only in the presence of water.

4. 29.4 Where is the line dividing land plants from algae?
Three possible plant kingdoms?
Embryophytes: Plants with embryos

5. Figure 29.7 Some highlights of plant evolution
Walled spores toughened by sporopollenin
Multicellular, dependent embryos
Apical meristems (root, shoot)
Presence of a waxy cuticle
[See book p ]

6. 29.5. Walled spores produced in sporangia.
Spores are haploid reproductive cells that can grow into gametophytes (n) by mitosis. Sporopollenin makes the walls of spores very tough and protects them against dehydration
Multicellular, dependent embryos
Develop from zygotes that are retained within tissue from the female parent

7. Apical meristem

8. Figure 35.18. Leaf anatomy (incl. waxy cuticle)

9. Figure 3.3 Vascular tissue – support against gravity and transport system in plants
Phloem
Cambium
Xylem: Water conducting cells
Lignin: Hard material embedded in cellulose cell walls for structural support

10. Figure 29.5 Alternation of generations: a generalized scheme

11. A hypothetical mechanism for the origin of alternation of generations in the ancestor of plants

12. Figure 29.7 Some highlights of plant evolution

13. Table 29.1 Ten Phyla (Divisions) of Extant Plants (Embryophytes)

14. Figure Charophyceans The closest algal relatives of land plants Chara (top), Coleochaete orbicularis (bottom)
29.4

15. Chara

16. Figure 29.7 Some highlights of plant evolution

17. 29.9. Bryophytes
Liverworts
Hornworts
Mosses

18. Figure 29.8 The life cycle of a moss (Polytrichum)

19. Figure 29.8 The life cycle of a moss (Polytrichum)

20. Moss life cycle gametophyte sporophyte archegonium sporangium spores
protonema

21. Marchantia, a liverwort

22. Gametangia: Archegonium of Marchantia (left), Anteridium of a hornwort (right)

23. A moss sporangium with a “spore-shaker” tip

24. Bryophytes
Liverworts
Hornworts
Mosses

25. Sphagnum, or peat moss: Peat bog in Oneida County, Wisconsin (top), close-up of Sphagnum (bottom left), Sphagnum "leaf" (bottom right)

26. A peat moss bog in Norway
Carbon reservoir  may help stabilize global atmospheric CO2

27. 29.11. More than 2000-year old bog mummy preserved in acid, oxygen poor Sphagnum wetlands
Peat, partially decayed organic material, harvested from peat moss (Sphagnum) wetlands. Decomposition is slow due to cold temperatures, acid conditions and little oxygen.

28. Figure 29.7 Some highlights of plant evolution

29. Xylem cells in angiosperms (see also Fig 35.10)
Lignin

30. Seedless Vascular plants - Ferns

31. Figure 29. 16 Lycophyta and Pterophyta
Figure Lycophyta and Pterophyta. Artist’s conception of a Carboniferous forest based on fossil evidence (some 350 million yrs B.P.)

32. Lycophytes: club "moss" (top left), many are epiphytes Pterophytes: whisk fern (top right), horsetail (bottom left), fern (bottom right)
strobulus
Lycophyta
Pterophyta

33. Figure 29.13 The life cycle of a fern

34. Figure 29.13 The life cycle of a fern

35. Life cycle of a fern: mature fern

36. Life cycle of a fern: sorus

37. Life cycle of a fern: sporangium

38. Life cycle of a fern: mature sporangium

39. Life cycle of a fern: germinating

40. Life cycle of a fern: gametophyte

41. Life cycle of a fern: sporophytes

42. Lycophytes: club "moss" (top left) Pterophytes: whisk fern (top right), horsetail (bottom left), fern (bottom right)
Lycophyta
Pterophyta

43. Figure 29.13 The life cycle of a fern

44. Heterospory: The sporophyte has two types of sporangia that produce two types of spores, which develop into either female or male unisexual gametophytes.
Spores:
Megaspore, developing into a female gametophyte, which will produce an egg
Microspore, developing into a smaller male gametophyte, which produces sperm

45. Which of the following is TRUE of seedless vascular plants?
They produce many spores, which are really the same as seeds.
Seedless vascular plants are all heterosporous.
Whole forests were dominated by large, vascular seedless plants more than 300 million years ago.
The few seedless vascular plants still living are large and rare.
None of the above are true. Vascular plants never form seeds.

46. Chapter 29 –Review (p. 616)
Concept Land plants evolved from green algae
Concept Mosses and other non- vascular plants have life cycles dominated by gametophytes
Concept Ferns and other seedless vascular plants were the first plants to grow tall