The fifth gallow?

[ololololo]

This unique symbol appears in the text several times, but it seems to me that given this number of appearances, it can't be called "unique".
   
   
   


There were also his appearances in botany, but I couldn't find them. Most often, there is no additional loop (as in the first two screenshots). 
Outwardly, it looks vaguely like an f with a second leg, but I think that's not the case, because we already have an f with a second leg:
   

What do you think?