A return to f25v - the dragon is the key, obviously, but is it basil?

[MarcoP]

In her discussion of ms Clm. 337 (Latin Dioscorides, late X Century) You are not allowed to view links. Register or Login to view. writes:

Beside and behind the plants and in the margins are scattered decorative, coloured drawings of snakes, scorpions, dragons, dogs and insects, which, it will be seen below, are a feature of Latin Herbals to draw attention to cures for the bites and stings of those creatures. The effect is decorative, almost humorous.

This feature is extremely common indeed, hence not very informative. The association of reptiles (snakes or dragons) with snake byte is preponderant. This particular illustration of Erba Gengiana also fits the pattern, since the plant is said to “heal snake bites” (vale a le morsure di serpenti, second to last row of the text).
The same plant is very differently represented in the Alchemical Herbal, sometimes in the company of a dragon (e.g. You are not allowed to view links. Register or Login to view.). The recipes are different, but also here the plant is said to help people “bitten by any venenous beast” (mordutus ab aliqua bestia venenosa).

The Gengiana illustration pointed out by Thomas is a good parallel for You are not allowed to view links. Register or Login to view. because:

• the leaves are similar to those of the Voynich plant
  
• accompanying dragons are not frequent in the ms (“Gengiana” could be the only case in which they appear, even if of course there are the usual zoomorphic roots)
  
• the dragons appear to be nibbling at the plant (the roots, in this case)