Greek kardamōmon blended names for peppergrass and an Indian spice plant. Latin cardamomum carries that combined name toward English.
The Random House entry at Collins also mentions French and Middle English intermediaries. The cards select only three stages; cardamon and cardamum are spelling variants, not extra steps.
Sources
- Merriam-Webster: cardamom
Word History supports the Greek and Latin forms and the blended plant names.
- Collins: cardamom
British entry gives variants and the Greek/Latin route; Random House Word origin mentions French and Middle English intermediaries.
- logeion.uchicago.edu · cardamomum
Meanings of the older forms on the word path.
- logeion.uchicago.edu · καρδάμωμον
Meanings of the older forms on the word path.