The frog

[-JKP-]

If the Vms botanical folios were a Latin herbal - which they're not IMO - and if frog pictures were generics - which they're not necessarily - then all pictures of all frogs with all plants would have similar meaning (significance). Which I don't think the case here.

So frog A in a Latin herbal may not be meant to convey the same as frog (B) carved in a misericord or frog © in a mural from Ephesus or frog (D) in the Voynich manuscript.

IMO the frog meant here is one that is renowed for its climbing to the heights of the 'peacock tree' ... where it sings.

But that's just my opinion, of course. Due mainly to first identifying the associated tree with (as you see) its 'peacock' -evoking root.

...

Animal images in Latin-, Italian-, German-, French-, Spanish- and English-language herbals are not generic, so I don't see why frogs would be. Snakes are usually the most common and they have many meanings:

• Snakes sometimes indicate the use of the plant (e.g., for snakebite).
  
• Snakes sometimes indicate the name of the plant (e.g., snake-root).
  
• Snakes sometimes are included as part bestiary in the alphabetical listing of the plant (e.g., in an English MS, a viper might follow the plant Verbena).
  
• Snakes sometimes indicate the shape of a part of the plant (like the root resembling the whole snake or the flower stalk resembling the tongue).
  
• Snakes sometimes indicate the habitat of the plant (grows where there are snakes, as in fields).
  
• Snakes sometimes indicate that the plant can be used to repel snakes or to protect from snakes.
  

There's nothing whatsoever generic about them. One has to go through most of the herbal to read the text and check the patterns to figure out specifically what they mean in that document (they sometimes have several meanings in the same manuscript, which is why reading the text is important) and since this is true of other animals besides snakes, I'm sure it would also be true of frogs.