Alan,

The Clan Stewart Society of the USA has this to say about the plethora of Stewart tartans:

Which Tartan do I wear?
The Stewarts are not just one clan. They consist of several major branches evolving from the descendents of various High Stewarts of Scotland.

There are several other older branches of the family. Some are Highland Clans and some are not. As a result, there are many Stewart Tartans. (Sixty-nine are officially registered and several are unofficial, using the main patterns with different background colors. "Camel Stewart" is an example.) Some tartans are general name-wide tartans that can be worn by anyone associated with the Stewarts. Others are specifically associated with a particular family or Clan (Stewart of Galloway, Stewart of Bute, Stewart of Appin, Stewart of Athol, etc.) The Hunting Stewart, is considered the National Tartan of Scotland and may be worn by any Scotsman. Protocol would dictate that only the current Royal Family would be "entitled" to wear the Royal Stewart tartan. If you have already invested in the Royal Stewart -- wear and enjoy your investment!

There are also other clans with tartans which are Septs and as such a part of the Stewart clan family. Boyd and Livingston are examples.

--http://www.clansstewart.org/faq.html
Also, the Tartans Authority's article on Royal Tartans has some brief descriptions about some of the Stewart tartans associated with the Royal Family:

http://www.tartansauthority.com/Web/...yalTartans.asp

I'm sure Matt will want to weigh on this as well! :mrgreen:

Cheers,

Todd