What does Anthea mean?
From Greek 'Antheia', derived from 'anthos' meaning 'flower, blossom'. Antheia was an epithet of the goddess Hera and associated with flowers.
What does Ianthe mean?
From Greek 'ion' (violet) + 'anthos' (flower), giving 'violet flower'. Borne by a figure in Greek mythology (an Oceanid) and used by Lord Byron. A minority of sources offer alternative roots, but 'violet flower' is the standard etymology.