: I would take this to mean that they learned how to use
: the roots for healing. The healing spell has its roots
: in the Heron initiation; it is not identical.
: Basically, they'd been using the root to make
: themselves immortal for a long time, but the healing
: spell was only discovered after Muirthemne was sacked.
Are you saying that they had the ability to use the healing spell before, but mistook it for the immortality spell? And it worked both ways? That's a wierd idea, but maybe it just might be true. If they had all kinds of healing spells, and the incantations for all of them were so much like the halt aging spell that they basically knew all forms but didn't use many of them...
Although, we do know from GURPS that the mandrake doesn't heal by itself. It merely holds energy for the healing spell so that the Heron doesn't need to use his own personal energy to cast it. If he did, then in the middle of a fight there would be herons dropping left and right from spending too much fatigue on their spells. That'd be something to see :)