The law of treason covers the circumstances which can give rise to the crime of treason, treason felony, misprision of treason (i.e. the concealment of treason) and who can commit those crimes.  There is no separate Scottish law of treason.
The crime of treason is based on the Treason Act 1351.  It declares what offences are to be treason e.g. levying war against the sovereign in Her Realm.  Certain of these forms of treason - compassing the death of or levying war against the sovereign - have been extended by judicial interpretation.  These extended forms are known as constructive treason.  The reservation also covers treason felony.  This includes acts to depose the sovereign, or prompt any foreigner to invade the UK or any other part of Her Majesty’s dominions or countries.  Treason can be committed by any person who owes allegiance to the Crown (i.e. in particular British citizens, or temporary UK residents.)
TABLE OF RESERVED MATTERS Part I: General Reservations General