A correct use of the word "exchange"

Let’s say I develop an internet site where producers can sell and consumers can buy flowers. I prefer to think of it as an exchange. From the point of view of native English speakers, which domain name would be more appropriate for the site: FLOWER.EXCHANGE or FLOWERS.EXCHANGE?

I have seen both notions of "commodity exchange" and "commodities exchanges", so am a little bit puzzled.

Thank you.

UPDATE: I can see that the "flower" in this case is called a noun adjunct, so it seems to be perfectly fine to use FLOWER.EXCHANGE. Just need a confirmation.