Гречка or Гречиха?

Question

Reading a few Wikipedia articles I come across different ways to spell buckwheat. One is Гречка (which is what I use when talking about buckwheat) and Гречиха (which I have never heard of before). What is the difference between the two words?

Answer 1

Гречиха is a plant and гречка is a cereal that is made from this plant..