1. CO 20

2. Fig. 20.1

3. Fig. 20.2

4. Outline
Introduction
Phylum Hepaticophyta - Liverworts
Leafy Liverworts
Phylum Anthocerophyta - Hornworts
Phylum Bryophyta - Mosses

5. Introduction
About 23,000 species of bryophytes.
Include mosses, liverworts, and hornworts.
Habitats range in elevation from sea level up to 5,500 m or more.
Bryophytes of all phyla often have mycorrhizal fungi associated with their rhizoids.
In some instances, fungi apparently are at least partially parasitic.

6. Introduction
Peat mosses are ecologically important in bogs.
Luminous mosses are found in caves and in other dark, damp places.
None have true xylem or phloem.
Many have hydroids.
Exhibit alteration of generations.

7. Phylum Hepaticophyta
Liverworts
Structure and Form
Most common liverworts have flattened, lobed thalli.
Gametophyte stage develops from spores.
When spores germinate they may produce immature gametophyte (protonema).

8. Phylum Hepaticophyta
Thalloid Liverworts
Best known species are in the genus Marchantia.
Thick thallus that forks dichotomously as it grows.
Consists of parenchyma cells with few, if any, chloroplasts.

9. Fig. 20.5

10. Fig. 20.4a

11. Fig. 20.6a

12. Fig. 20.4b

13. Fig. 20.6b

14. Fig. 20.6

15. Fig. 20.7

16. Fig. 20.6c

17. Asexual Reproduction of Marchantia

18. Leafy Liverworts
Always have two rows of partially overlapping “leaves” whose cells contain distinctive oil bodies.
Often have folds and lobes.
Archegonia and antheridia are produced in cup-like structure.
At maturity, sporophyte capsule may be pushed out as the seta elongates.
Germinating spore produces a protonema.

19. Fig. 20.8

20. Phylum Anthocerophyta
Hornworts
Structure and Form
Mature sporophytes look like miniature greenish-blackish rods.
Only about 100 species worldwide.
Thalli have pores and cavities filled with mucilage, that often contain nitrogen-fixing bacteria.

21. Fig. 20.9a

22. Hornwort Sporophyte

23. Hornworts
Asexual Reproduction
Fragmentation
Separation of lobes from thallus.
Sexual Reproduction
Archegonia and antheridia are produced in rows beneath the upper surface of the gametophytes.
Have both unisexual and bisexual plants.

24. Phylum Bryophyta
Mosses
Structure, Form, and Classes
About 15,000 species of mosses currently known.
Divided into three classes:
Peat Mosses
True Mosses
Rock Mosses

25. Mosses
“Leaves” of moss gametophytes have no mesophyll tissue, stomata, or veins.
Blades are nearly always one-cell thick, and are never lobed or divided.
Initially formed in three ranks and usually end up appearing to be arranged in a spiral or alternately on an axis that twists as it grows.
Sexual Reproduction:

26. Fig

27. Fig

28. Fig

29. Fig

30. Fig c

31. Fig a

32. Fig b

33. Phylum Bryophyta
Human and Ecological Relevance
Pioneer Species of Primary Succession
Indicators of Surface Water
Packing Material
Peat Mosses
Soil Conditioner
Poultice Material
Fuel

34. Review
Introduction
Phylum Hepaticophyta - Liverworts
Leafy Liverworts
Phylum Anthocerophyta - Hornworts
Phylum Bryophyta - Mosses