I’ve seen such roses (but in smaller sizes) used in Irish crochet. The idea is not complicated, and I was able to come up with my own pattern. For the roses shown, I used cotton yarn (can’t tell the size and brand as it’s been in my stash forever).
Motifs, panels and rows make up these beautiful Christmas Afghans. Snowflake Rose’s motifs are join-as-you-go and create a stunning lacy snowflake; Christmas Flowers works up quickly using double-strands of yarn; and Peppermint Stripes brings to mind.