This famous herb gives us the classic curry colour (it's also known as Haldi).
Turmeric is a member of the ginger family, which looks similar to fresh root ginger. It is boiled, dried and ground to make a powder which tastes really bitter on its own and it has a really intense bright yellow colour, so only a little should be used (in fact, turmeric is mainly used as source of colouring but it does give a gentle, woody aroma to your dish). Be warned though, turmeric will stain utensils and clothes (!) but it is absolutely essential for Indian cooking.
This herb is highly regarded as a super spice and is said to contain has anti-inflammatory and antibacterial properties. It is also a natural decongestant, it's used as an antiseptic paste to treat wounds in India and right now it's being tested as a remedy to help relieve some people suffering from Alzheimer’s.
In Indian cooking, it's believed that turmeric helps protect the stomach lining from the harsh intensity of chilli and other spicy ingredients.