I have just got hold of a copy of John Ashdown-Hill's book on Eleanor Talbot, Eleanor, the Secret Queen: The Woman Who Put Richard On The Throne. A review will follow in due course either here or at The Yorkist Age probably the latter given that it's on-topic.
I have had a brief thumb through it and one thing has already made me say 'wow!' though it's nothing to do with the main subject matter.
Over the last few years I've written a fair bit of fiction about Elizabeth Talbot, Eleanor's sister. Most of it is doomed to die unseen, as it doesn't really fit into a novel about Richard III. In fact, Elizabeth as a character is a bit like Edmund Mortimer in reverse, envisaged as a major player, she is going to end as a bit part.
Anyway, I tend to focus on characters until I can see them in my mind's eye, and my image of Elizabeth was of her standing in a garden, among lots of borage plants. (I even remember checking when borage flowers so I could get the scene right.)
Guess what her personal flower was, as used on her seal, according to John A-H? Yes, you've got it - borage.