It is in essence a combination of two roses, one on top of the other.
A standard heraldic rose should not be depicted this way but has only the five outer petals.
[1] An example of this heraldic charge is the Tudor rose, which is (most usually) a double rose gules and argent, barbed and seeded proper, but as it is so common in English heraldry it is often just blazoned as a "Tudor rose" or a "Tudor rose proper", for instance in the coat of arms of the Royal Borough of Greenwich, London.
These varieties go back to pre-heraldic times.
This heraldry-related article is a stub.