About roses?

Question

is a rose a dicotyledon or monocotyledon seed

Answer 1

It's a dicotyledon, like the majority of flowering plants.

Monocotyledons are plants like grasses and lillies where a single "leaf", or cotyledon emerges from the seed. With dicotyledons, the first "leaves" come as a pair.

Answer 2

A rose is a dicot.  The veins on the leaves are branching, whereas monocots have parallel veins in their leaves (like grass and cattails).