Scottish Green Party - 19. Is the Scottish Green Party organizationally independents of the Greens South of the border?
Yes. When parties were required to register, their application was initially rejected (parties have exclusive use of a name or similar names), but it was eventually allowed to register (the register for Great Britain allows a party to indicate that they will contest elections in each of England, Wales, and Scotland). Most parties will indicate that they will be active in all 3, some such as PC or SNP will indicate only their home area. The "Green Party" (full, official name) has indicated that they will only contest elections in England and Wales.
Candidates may use different descriptions on the ballot (with permission of their party) and candidates north of the border will often include "Scottish" in their description.
The Northern Ireland party register is separate from that for Great Britain, but a party may register on both. The Tories have, Labour and LibDems have not. The "Green Party" (full, official name) registered in Northern Ireland is separate from that in England&Wales, and has a party address in Dublin. I assume it is the same organization as the party in the Republic of Ireland.