Which fruit is traditionally used to make marmalade?

In russian language we call marmalade mermelad

{H3LLO_K3TTY}, it’s not the orange it’s the peel that’s sour/bitter. A taste some people really like.

{H3LLO_K3TTY}, Seville oranges have a sharp, slightly bitter flavour and they are usually used to make preserves such as marmalade. When the oranges are ready to pick men go around Seville climbing ladders to reach them.

Jamie sour oranges doesn't exist 💀

I thought it was the sour oranges

i don't like oranges