Bryophytes Oldest plants ~400 million years old Autotrophic, multicellular eukaryotes 18,600 species...

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Transcript of Bryophytes Oldest plants ~400 million years old Autotrophic, multicellular eukaryotes 18,600 species...

Bryophytes

• 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

• 4 major divisions• Pterophyta- ferns• Psilotophyta- whisk ferns• Lycophyta- club mosses• Sphenophyta- horsetails

Lycophyta

• 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

• 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 fiddleheads-

mature leaves- fronds

FernsSorus- clusters of sporangia- spore producing tissue

Fern life cycle

Tree fern