When there are no more individuals of a species (plant or animal) alive anywhere in the world, the species is said to be extinct. A decrease in the species diversity progresses to extinction if left uncontrolled. Extinction is also known as the process of dying out. The process is a completely natural part of evolution. But sometimes extinctions happen at a higher and a faster rate than usual. Factors such as over-exploitation, large body size, small population, massive habitat loss and position at a higher trophic level favor extinction. A plant podophyllum is at the verge of extinction due to over-exploitation. So, the correct answer is 'Podophyllum'.