Chapter 22 Diversity of Plants 22-1 Nonvascular Plants

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  Small in numbers
  
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  Need water because of the lack of vascular tissue
  
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  Small size
  
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  Gametophyte generation is dominant
  
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  Gametophyte produces 2 kinds of reproductive features
  
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    Antheridium – male
    
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    Archeogonium – female
    

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  Mosses
  
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  Leaves are 1 cell think
  
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  Upright or creeping stems
  
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  Occurs in a wide variety of habitats
  
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  Rhizoids anchor to soil
  
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  Grows in groups
  
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  Example: peat moss
  

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  Liver warts
  
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  Grow in many environments
  
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  Rhizoids 0 1 elongated cell
  
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  Shiny or oil surfaces to reduce water loss
  

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  100 species, i.e. hornwarts
  
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  1 chloroplast in each cell
  

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  Liverwarts may be first land plants over 430 mya
  

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  Vascular tissue
  
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  Adapted to changes in water availability
  
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  Alternation of generation
  
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    Sporophyte is dominant
    
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  Leaves are adaptive structures to protect developing reproductive cells
  
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  Spore bearing leaves form strobilus which releases spores that become gametophytes (prothallus). These form the male and female reproductive parts
  

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  Club mosses, spike mosses
  
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  Has roots, stems, leaves
  
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  Single vein of vascular tissue
  

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  Horsetails
  
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  15 species
  
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  1 meter tall
  
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  Found in marches, stream beds, but also drier environments
  
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  Reproduce like lycophyta
  

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  ferns
  

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  Appear 400 mya
  
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  Found in many environments
  
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  Sporophyte generation has roots, stems, and leaves
  
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  Main stem is underground (rhizome)
  
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  Leaves form fronds
  
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  First to evolve vascular tissue on leaves
  
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  Fern spores are produced in sporogia. Clusters are called sorus
  

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  390 mya during the Paleozoic (Carboniferous)
  
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  Largest species died out over 280 mya
  
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  Evolution of vascular plants allowed plants to grow larger
  

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  Seeds produced by sporophyte generation
  
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  Seeds develops into male and female gametophytes
  
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    Males – pollen
    
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    Females- ovule
    
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  Sperm and egg join to form the sporophtye during the process of fertilization. Zygote is formed which develops into an embryo (diploid sporophyte)
  
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  Most seed plants do need water to reproduce
  
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  One or more cotyledons (seed leaves that sore and absorb food for the embryo)
  

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  Food supply for embryo
  
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    Used by plants until leaves are formed
    
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  Many form seeds in cones or flowers
  
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    Called gymnosperms
    
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  Flowering plants are called angiosperms
  
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    Produce seeds enclosed in fruit
    
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    Used for protection and seed dispersal
    

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  100 species
  
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  Found in tropic and sub tropics
  
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  Separate male and female plants
  
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  Motile sperm
  

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  Separate male and female plants
  
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  High tolerance for pollution
  

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  Trees and shrubs
  
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  Pines, firs,
  
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  Most have male and female origins on different branches
  
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  Reproductive structures found in cones
  
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  Most are conifers retain leaves
  
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    Reproduce in spring
    
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  Deciduous tress
  
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    Loose leaves
    
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    Reduces water loss
    

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  240000 species
  
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  Roots, stems, and leaves
  
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  Produce flowers
  
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  Seeds enclosed in fruit
  
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    Protects embryo and aids in dispersal
    
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  Classes:
  
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    Monocots (1 seed leaf): grasses, orchids, lilies, palms. Leaves in multiple of 3
    
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    Dicots (2 seed leaves): trees, shrubs, wild flowers. Leaves in multiples of 4 or 5
    

Annuals- live 1 year. To seed, grow, produce and die; herbaceous (no woody tissue)

Biennials- 2 years; carrots, leaks, turnips

Perennials- 2 + years

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  300 mya