Transcript Slide 1 - leportebiology

Bryophytes
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Oldest plants ~400 million years old
Autotrophic, multicellular eukaryotes
18,600 species
Mosses, Liverworts, Hornworts
Bryophytes
• Nonvascular- cannot transport water or nutrients
or starch
• No true leaves, roots, stems• Small <20 cm
• 3 features of land plants
– Cuticle
– Cellular jacket around gametes
– Large gametophytes separate from sporophyte
Mosses
• 10, 000 species
• Grow in moist areas- water still needed for
sperm to move to egg
• Peat moss- used for fuel
• Rhizoids- root-like structures used for
attachment to soil
Mosses
Hornworts
Liverworts
Bryophytes life cycle
Seedless Vascular plants
• Next group to evolve further features for
life on land
• Xylem and Phloem- move water and sugars
throughout the plant
• 13, 000 species
• True roots, leaves, stems- rhizomes
• NO SEEDS but use SPORES
• Large sporophyte
Seedless vascular
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4 major divisions
Pterophyta- ferns
Psilotophyta- whisk ferns
Lycophyta- club mosses
Sphenophyta- horsetails
Lycophyta
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1,100 species
Club mosses- still need the water to reproduce
Commonly called “mini pines”
Cone-like structures called a strobilus contain
spore producing leaves
Club Mosses
Psilotophyta
• Whisk ferns- not true ferns
• Rhizomes- short branched, horizontal
absorptive stems that grow underground
• Reduced leaves
• Photosynthetic branches
Psilotophyta
• Whisk ferns- not true ferns
• Rhizomes- short branched, horizontal
absorptive stems that grow underground
• Reduced leaves
• Photosynthetic branches
Whisk Ferns
Horsetails
Pterophyta
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Ferns- 12,000 species
Largest and most diverse group
Mostly tropical
1 cm across to 25 m tall
Vascularized rhizomes give rise to roots and
leaves
• Sporangia on leaves release spores
Ferns
• Stomata in leaves
• Life cycle dominated by sporpohyte (1st time
we see this)
• Eggs and sperm produced- need water
• Immature leaves are called fiddleheadsmature leaves- fronds
Ferns
Sorus- clusters of
sporangia- spore producing
tissue
Fern life cycle
Tree fern