Plant Taxonomy: Summary & Characteristics

Defining Characteristics of the Plant Kingdom:

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

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	Central Star-Shaped
Stem Vascularisation	Scattered	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