Native plants are our plants, the ones that belong here.
A broad definition might be that native plants were indigenous to the landscape before European settlers arrived in North America. Florida was exposed to plant introductions from Europeans and Native Americans hundreds and even thousands of years ago. The whole point about whether a plant is native or not may seem to be simply a historical issue. However, is highly relevant to ecology and biodiversity. Plants that have existed in an area or a plant community for tens of thousands of years evolve complex interrelationships with the organisms of that area and that plant community.