Nelumbo is a genus of aquatic plants that are commonly called "lotus". There are two known living species and one known extinct species:
Nelumbo nucifera is a plant found throughout east, south, and southeast Asia. The roots, stem, pod, and seed can be eaten. The plant is cultivated in many parts of the world and is prized as a beautiful water flower to be used in ponds. It's also considered sacred in some religions.
Nelumbo lutea is found in the Southern United States, Parts of Central America, and the Caribbean. Like N. nucifera, N. lutea is edible. However it is not domesticated like N. nucifera, and grows wild.
Nelumbo aureavallis is an extinct Eocene species found from a few fossils of it's leaves and flower bud found in North Dakota.
Here's a lotus root recipe:
1/2 lotus root, sliced very thinly
1 piece of fresh ginger about 1 inch / 2 cm or so long, peeled and chopped
2 garlic cloved, peeled and chopped
1 1/2 cups of roughly chopped green onions
2 Tbs. hot red chili pepper, finely chopped Oil
Vinegar for the lotus root water
1 Tbs. sesame seeds
1 1/2 Tbs. soy sauce
1 tsp. sesame oil
Put the sliced lotus root into vinegar water as you slice it, as described above. Drain well just before cooking.
Heat up a large frying pan with the oil. Add ginger and garlic, and stir fry until the oil is very fragrant. Add the drained lotus root slices in a single layer. Cook until the lotus root slices start to change color - they turn a bit translucent looking. Turn over and cook a couple more minutes.
Add the chili pepper and green onions, and stir-fry. Add the sesame seeds, pepper, soy sauce and sesame oil. The lotus roots should get a bit caramelized from the soy sauce. Serve hot or cold.