lecture notes the plant itself 1. the fitness of the environment Henderson (Harvard) The plant kingdom includes all plants that have ever lived. 1. consists 15 or so phyla first plants in ocean 1st advance - land conquered 2nd vasculature system a. Tracheids - conducting + strength b. vessels 3rd -> mechanisms for getting light. 1. growth at tips 2. secondary thickening ferns wiped out in permian in which the habitat was severe. gymnosperms survived because 1. Tracheids - strength + conduction, 2. Secondary thickening 3. Sclerophyll - foliage reduced in surface + heavily cuticized 4. Developed buds - 5. Seed habit - eliminated hazards? sex cells united at once - made possible rest period. Angiosperms 1. very versatile,