Flora has evolved to live in extreme conditions and a wide variety of locations and seen as the eldest 'creatures' on the planet. Their struggle for life, like animals (only usually much slower), is about food (including parasitism and 'flesh-eating'). They strive to find water, to procreate: notably pollination-mostly by animals and semination - gliding or by weather conditions, or more primitive ways such as spores. They have a varied defense (thorns, spines, toxins etc.). Specific is the need for light, the fuel of photosynthesis, leading to a hierarchy of light-related levels, because not growing high enough in time can be lethal.
—KGF Vissers