Common horsetail, or Equisetum arvense
Horsetail is a shoot that tastes and looks a little like asparagus or samphire, and best harvested in April. Very good mineral qualities: rich in selenium and silica: for bones, teeth, hair, nails.
Only one species - common horsetail, or Equisetum arvense - should be used. Commonly seen on waste ground or by water.
I clean mine carefully in running water, cut out the hard little collars, clean again, boil quickly in water, drain, then simmer for a few minutes in mirin (rice wine , but sherry would do) , soy sauce, maybe a little rice vinegar and brown sugar. Serve with fluffy rice and green tea, or maybe with a pork or chicken stir fry. Some people stir an egg through this.