Transcript Nonvascular Plants

Caitlin Anderson
History
 The first land plants were nonvascular.
 Started appearing about 460 million years ago.
 Ancestor is green algae.
 They used to all be classified under Bryophyte,
but now there are three divisions.
How they are similar
to other Plants
 All plants need:
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Water
An energy source (mostly the sun)
Spreading out of young plants to eliminate competition with
parent plants
Characteristics
•Lack Vascular tissues
•Move water by osmosis and diffusion
•Grow only 1-2 cm high
•Grow in large groups
•Don’t produce seeds or flowers
•Not typical plant stems or leaves
•Rhizoids instead of roots (they
don’t absorb water or nutrients)
•No stomata
Reproducing
 Sexual and Asexual
 Sexual is more common
 Gametes are formed within gametangia
 Males’ have antheridium and make flagellated sperm
 A female has archegonium and makes one egg
 Water is needed for the sperm to reach the egg
(rainwater or dew usually works)
continued
 The egg is fertilized and the diploid zygote splits by
mitosis and turns into an embryonic sporophyte.
 This grows into a long stalk that stays attached to the
female plant.
 A little capsule, sporangia, forms at the end and
haploid spores are created by meiosis here.
 The spores are dumped out andeventually grow into
mature plants.
http://www.coolschool.ca/lor/BI11/unit7/U07L02.htm
Alternation of generations
 Alternation of generations- the cycle in which a plant
creates two multicellular generations
 Diploid generation is called the sporophyte
 Haploid generation is called the gameophyte
 The gameophyte is the dominant
generation in nonvascular plants
 The sporophyte depends on it for
support
Bryophyta
 Mosses
 Most common nonvascular plants
 At least 10,000 species
 Some vascular tissue
 The sporangia is more complex than other plants
 Use each other to stay standing
 Have “stems” and “leaves” that are similar to
vascular plants
continued
 Seven types of mosses
 Andreaeidae
 Sphagnidae
 Tetraphidae
 Polytrichidae
 Buxbaumiidae
 Bryidae
 Archidiidae
 More than 95% of mosses are Bryidae
Sphagnum fuscum
Tayloria mirabils
Holomitrium crispulum
Hepatophyta
 Liverworts (hepatics)
 Around 8,000 different species
 About 1mm to 50mm
 Simplest plants
 Coil shaped sporangia
 Can form gemmae cups that
hold cells that are released
with rain to form new plants
(asexual reproduction)
continued
 Ancient people thought they
cured diseases of the liver
 Often confused with Hepatica
plants because of the hepatics
name.
 Two types: leafy and thallose
 Thallose is more common
Leafy Liverworts
 About one cell thick
 Easily identified as mosses
 Two or more sections
 Two rows of leaves usually
 A third row of smaller leaves often occurs (only visible
by microscopes)
Thallose Liverworts
 No stem-leaf structure at all
 Surface is like a flat plate
 Can be several cells thick
 Can be divided into sections that vary in size
 Some have pores
Metzgeria furcata
Tritomaria quinquedentata
Conocephalum conicum
Anthocerophyta
 Hornworts
 About 100 species
 Have one Chloroplast per cell
 Hornworts get the name from the sporophytes
 Look similar to thallose liverworts
Commonly found
• Damp and shady areas
• Rocks
• Trees
• Near rivers
• Mostly wet regions
In Our Area
 Floating Liverworts and Umbrella
Liverworts are very common in Minnesota
 Hornworts are rare in Minnesota
 St. Paul and Minneapolis
 Near White Bear Lake, Lake Calhoun, Lake
Osakis, and Alexandria
Moss in Minnesota
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Little Saw Moss
Bud-headed thread moss
Egg-leaf true moss
Bug-on-a-stick moss
Hair-pointed thread moss
Mowed mosquito moss
Pigmy plume moss
Extinguisher moss
Cave moss
Red twisted bog moss
Cushion peat moss
Shortleaf chalk moss
Swan moss
And more
Why Nonvascular Plants are
Important
 They are first plants to colonize a region.
 Once mosses die, they decompose and create soil for
new plants.
 They can be food for some animals.
 Peat mosses can be used by humans for fuel.
Other info
 They help indicate how pure an environment is. They
are very sensitive to air and water pollution. That is
why they are more common in country areas.
 Mosses are often used in decorating a garden.
 They are so small that they don’t have much impact on
their surroundings.
Questions
1.
What are the three divisions of nonvascular plants?
A. Thallose, Musky, Bryophytes
B. Leafy, vascular, moss
C. Bryidae, Sphagnidae, Hepatica
D. Bryophyta, Anthocerophyta, Hepatophyta
2. What is the most common type of moss?
A. Mossy
B. Buxbaumiidae
C. Archidiidae
D. Tetraphidae
E. Bryiade
3. What is not true about liverworts?
A. There are two types
B. Ancient people thought they could cure diseases of the heart
C. They are part of the Hepatophyta group
D. Often confused with the Hepatica
more
4. What is true about alternation of generations?
A. Gameophytes are always dominant
B. Sporophytes are always dominant
C. The gameophyte is dominant in nonvascular plants
D. The gameophyte is dominant in vascular plants
5. What nonvascular plants are found in Minnesota?
A. Lots of hornworts, umbrella and floating liverworts, and no mosses
B. Few hornworts, umbrella and floating liverworts and, tons of mosses
C. Few hornworts, puddle and sinking liverworts, and a few mosses
D. There are absolutely none in Minnesota
The last few
6. Which kind of nonvascular plant is considered the simplest in structure?
A. Liverworts
B. Mosses
C. Bryiade
D. All of the above
E. None of the above
7. Explain how nonvascular plants differ from vascular plants
8. Explain briefly how plants reproduce
Resources
 http://www.hiddenforest.co.nz/bryophytes/liverworts/intro.htm
 files.dnr.state.mn.us/input/rules/ets/mosses.pdf
 http://www.bryology.org/bryodesc.html
 http://www.cartage.org.lb/en/themes/Sciences/BotanicalSciences/ClassificationPla
nts/Cryptogamia/Bryophyta/Nonvascular/nonvascular.htm
 http://academickids.com/encyclopedia/l/li/liverwort.html
 http://www.sparknotes.com/101/biology/the_evolution_and_diversity_of_land_pla
nts/nonvascular_plants.html