Endemic
Describes a plant found naturally in one particular place and nowhere else on Earth.
An endemic plant has a natural range limited to one area: an island, a mountain range, a country. All endemics are native, but most natives are not endemic. Islands and isolated mountains are rich in them. The Haleakala silversword grows only on one volcano on Maui in Hawaii. South Africa's Cape region holds thousands of plants found nowhere else. Because their range is small, endemic plants are easily lost to building, grazing, fire or invasive species.