The largest seed in the world that we know about is Coco De Mer palm tree seed. They weigh 30 kg and are roughly 50cm across. They are native to The Seychelles islands on the African continent and are found no where else in the world except in human cultivation.
The Smallest seed that we know of is from the Orchid flowers that are often sold in supermarkets and florists. Their seeds are so small that they resemble dust. They are so small that the need a fungus partner to get them growing because they won't germinate on their own. You need a microscope to see the individual seedlings.
