In The Silver Chair, what is the name of the witch queen?

In The Silver Chair, the witch queen is the Lady of the Green Kirtle. She rules Underland and secretly holds Prince Rilian captive, intending to use him as part of a plan to conquer Narnia.

The Lady first appears as a mysterious green-clad enchantress who misdirects Eustace, Jill, and Puddleglum toward the giants' castle of Harfang. Later, the travellers discover that Rilian's apparent madness is actually the result of her enchantment. He is bound to a silver chair whenever he begins to remember his true identity.

A common mix-up is calling her the White Witch or Jadis. Both women are associated with Narnian witchcraft, but Lewis's text presents them as separate characters. The Lady is also called the Queen of Underland, which is her title rather than her personal name. At the climax, she transforms into a green serpent, revealing that she was responsible for the death of Rilian's mother.