This fern is called Rainbow Leaf  (Kwichij Panga)  because its iridescent color suggests the rainbow.   Because the fern looks like a rainbow it is used to cure “rainbow sickness” (Kwichi Paju).  Kwichij Paju is the Kichwa name given to “shingles”.   Shingles also recalls the rainbow because the rash or sores it produces breaks out in an inflamed red arch that follows a nerve.  To Amazonian Kichwa this red arch looks like the rainbow and so is believed to be caused by the rainbow.  To treat shingles the rainbow leaves are heated in water and placed over the sores.  Alternatively the affected area is subjected to a steam bath in the vapors of the rainbow leaf.

Diplazium pinnatifidum (Pteridphyta); Kichwa:  Kwichij Panga “Rainbow Leaf”