Named in Capitulare de villis
Marshmallow
Althaea officinalis
What was written
Marshmallow is listed in the Capitulare de villis. Its root is full of mucilage, and a confection made from that root is the ancestor of the sweet that still carries its name — though nothing sold under that name today contains any part of the plant. The name Althaea comes from a Greek verb meaning to heal, which is the kind of etymology the monastic writers noticed and repeated.
The plant itself
A tall grey-downy perennial of brackish marshes and ditch banks, with soft velvety leaves and pale pink flowers. The whole plant, root included, is unusually rich in mucilage, which is what makes the root soften rather than dissolve in water.
Still growing
Since the plant was written into that garden list, botanists, herbaria and ordinary observers have recorded finding it 63,959 times.
Live count from GBIF, cached for a week.