What is special about Voynich plants?

[Sam G]

The first three points are clear to me (and also match some of Koen's observations).
Could you please specify which illustrations present the features in your fourth point?

I guess that one is You are not allowed to view links. Register or Login to view., that was discussed You are not allowed to view links. Register or Login to view..

That would be one example.

93r is another example.  There are red lines which are especially prominent in the roots, but also found in the stem.

More examples would be 4r, 2r, 13r, 35r, 38v (not a complete list).

2v has red lines in the stem, but they have been painted over with green, so you have to look carefully to see them.

14r is interesting, because the central stem is filled in entirely with red, but the smaller branches only have thin red lines in them, with no attempt to fill them in entirely.

47v is another interesting example, because the top of the root is "highlighted" with a red line, yet we find basically "the same" root at the top of 102r2 but without the red, possibly suggesting that the red is not an intrinsic part of how the root is supposed to appear visually, but may instead indicate an "emphasis" in one case that is not present in the other case.

Good examples of dotted lines would be along the edges of the leaves in 3r and around the top of the root in 45v.  In both of these cases the dotted lines seem to be emphasizing a particular type of curvature (though I'm not certain that they actually serve that purpose).

What I would like to know about these features is:

1) Can they be found in other European herbals?

2) Is there some aspect of real plants that these features could plausibly be taken as an attempt to depict with visual accuracy?

If the answer to both of the above is "no", then it seems we have a common property of the VMS botanical illustrations that represents a unique form of symbolic representation (which would seem to imply that whoever composed the illustrations possessed a "botanical theory" of some kind, as stated in my previous post).