http://www.pfaf.org/leaflets/edible_uses.php

There are over 20,000 species of edible plants in the world yet fewer than 20 species now provide 90% of our food. However, there are hundreds of less well known edible plants from all around the world which are both delicious and nutritious.
685 Edible Flowers
Fruit (1723)
2449 Edible leaves
1181 edible roots
Pollen (18)
Sap (80)
Seeds: nuts, cereals, peas and beans (1326)
Seedpod (eg. Okra, French and Runner beans (118)
Stems (344)
Manna - a sweet substance that exudes naturally from certain plants, usually from the stems (40)
Nectar - produced in such abundance by some flowers that it can be harvested fairly easily (30)
Inner bark - the bark that is found just beneath the tough outer bark of trees and shrubs (141)