Defining Characteristics of the Plant Kingdom:

  • Multicellular
  • Terrestrial
  • Embryophytes
  • Photosynthetic (almost all)
  • Eukaryotic

4 Major Groups

1.     Non-Vascular Plants (Bryophytes and Friends)

  • No vascular tissue – therefore must rely on surrounding moisture and osmosis to move fluids through their bodies.
  • Small in stature, and simplistic – NO organs (roots, leaves, stems) (Rhizoids = root-like structures that provide minimal anchorage / absorption).
  • Pioneer plants – lay the foundation for other plant growth, prevent erosion.
  • Use spores to reproduce (sexual) – require water for sexual fertilization. Also capable of fragmentation (asexual).
  • Alternation of Generations – lush “mat”-like body = haploid gametophyte generation (produces gametes through mitosis), stalk-like sporophyte generation (diploid) forms when gametes unite and produces haploid spores (that grow into individual male / female gametophytes that produce gametes through mitosis, etc.) through meiosis.
  • Examples = Mosses, Liverworts, Hornworts, (3 non-vascular phyla), All groups below = Vascular plants = Tracheophytes

2.     Vascular Seedless Plants (Pteridophytes and Friends)

  • Have vascular tissue to transport fluids.
  • Diverse form – 2mm to 15 m in height. True roots, stems, leaves.
  • Like mosses = Pioneer plants.
  • Alternation of Generations – familiar fern body (frond) = diploid sporophyte generation (underneath the fronds are brown sporangia that produce spores via meiosis). Heart shaped prothallus at base of frond = haploid gametophyte generation which produces gametes via mitosis. 
  • Use spores to reproduce (sexual) – require water for sexual fertilization. Also capable of fragmentation (asexual).
  • Examples = Ferns, Horestails, Club Mosses, Whisk ferns (4 vascular, seedless phyla), All Groups Below = Seed Plants = Spermatophytes

3.     Vascular Seed Plants (Naked) – Gymnosperms (Conifers and Friends)

  • Have vascular tissue
  • Cones = reproductive structures
  • Pollen to transport sperm – no need for water
  • Leaves typically = needles/scales
  • Examples = Conifers (pines, firs, yew, junipers, cedars), Gingkos, Cycads, Ephedra (4 vascular seed phyla)

4.     Vascular Seed Plants (Covered) – Angiosperms

  • Have vascular tissue
  • Flowers = reproductive structures
  • Pollen to transport sperm – no need for water
  • 2 major classes: Monocots and Dicots
Characteristic Monocot Dicot
# of Seed Leaves 1 2
# of Flower Petals 3 / multiples of 3 5 or 4
Leaf Venation Parallel Net-like
Root Vascularisation Ring

dicot-ring

Central Star-Shapeddicot-center-star-shaped
Stem Vascularisation Scattered

monocot-scattered

Ring

Monocot-ring

 

Examples Orchids, lilies, palms, irises, wheat, rye, barley, oats, corn, bananas, onions

30,000 species

Most trees, shrubs, vines, flowers, fruits, vegetables, and legumes.

200,000 species

 

Leave a Reply

Be the First to Comment!

avatar
wpDiscuz