The rangers guild has for time immemorial had the ability to pick herbs as well as any Animist.
Thus a suitably skilled ranger can pick wurtfoil.
It has been a constant thorn in the side of the rangers guild that although they have ultimate herbs available to them
the nature of wurtfoil means that they rarely get access to it.
This does not however mean that they never get access to it.
So although wurtfoil is largely controlled by the Animists guild it is not due to some form of unique picking ability, therefore you
should not be suprised to see rangers both holding and using wurtfoil.
Hope that clears things up.
Written by my hand on the 3rd of Hindyear, in the year 1097.