Viola (odorata or tricolor)

[Bernd]

This is why I believe the VM drawing was likely created from a pressed plant. It would have begun wilting almost immediately after harvesting, becoming slightly limp. Just straightening it out on a surface results in upside-down flowers, this would not even require pressing. But flowers would have eventually rolled up while the petals in the VM illustrtion are nicely stretched out.

As of why V. tricolor / arvensis are missing from herbals before the very late 15th century -  I have no idea. The question is - are we really missing text or just illustrations?