Ok, this is my last post today in this thread, sorry for filling it up with speculation and image comparison, but I thought it was interesting...
Ok, lastly, I found a voynich image which resembles Catha edulis. This plant contains beta- keto-amphetamine compounds, and has been known as a stimulant in the old world...
-eg
entheogenic-gnosis attached the following image(s):

manuscrito049.jpg
(196kb) downloaded 24 time(s).
Catha edulis 3.JPG
(62kb) downloaded 24 time(s).
Catha edulis 1.gif
(39kb) downloaded 24 time(s).