What is special about Voynich plants?

[MarcoP]

How are the images in the first section of the Voynich manuscript different from other ancient herbals?
I would be interested in other people's opinions.

I attach visual comparisons between the Voynich ms and other manuscripts. I used four of the identifications listed by Derek Vogt on the site of You are not allowed to view links. Register or Login to view..

The plants are:

Betonica (Voynich You are not allowed to view links. Register or Login to view.)
Malva officinalis, marsh mallow (Voynich You are not allowed to view links. Register or Login to view.)
Papaver, poppies (Voynich You are not allowed to view links. Register or Login to view.)
Plantago (Voynich You are not allowed to view links. Register or Login to view.)

The intent is not to comment on these specific identification hypotheses, but only to compare images between different manuscripts. 

Manuscripts, left to right:

• You are not allowed to view links. Register or Login to view., Pseudo-Apuleius Platonicus, England, 2nd half of the 12th century
  
• You are not allowed to view links. Register or Login to view., Tractatus de herbis, Southern Italy, between c. 1280 and c. 1310
  
• You are not allowed to view links. Register or Login to view., Manfredus de Monte Imperiali, Liber de herbis et plantis, Southern Italy, first half of the XIV Century
  
• The Voynich ms, first half of the XV Century
  
• You are not allowed to view links. Register or Login to view., Herbal of Giovanni Cadamosto, Veneto, 3rd quarter of the XV Century (before 1472)
  

Of course, you don't need to comment on these specific plants and manuscripts. Different comparisons are definitely welcome!