Digging over the patch next to the sweet cicely, I found the tag that must have come with the first plant 20 or more years ago. It explains how not only the leaves and seeds can be used but also the root. Gerard in his Herbal knew this well:

‘The roots are likewise most excellent in a sallad, if they are boiled and afterwards dressed as the cunning Cooke knoweth how better than my selfe: nothwithstanding I use to eat them with oile and vinegar, being first boiled; which is very good for old people that are dull and without courage; it rejoiceth and comforteth the heart, and increaseth their lust and strength.’

Indeed the root does taste good. I did as Gerard instructed and added it to a mixed salad.

In Flora Britannica, Richard Mabey also mentions how every part of the plant can be eaten. All taste of aniseed with a sweet undertone. Indeed sweet cicely was known as a sweetener in the Middle Ages.