I want to know the answer to the following question:
How many plants can only be found on Norfolk Island?
All the background I'm provided with is that "The Norfolk Island palm (Rhopalostylis baueri) and the smooth tree-fern (Cyathea brownii), the tallest tree-fern in the world, are common in the Norfolk Island National Park but rare elsewhere on the island.". Is that enough to answer the question?
Answer: no