[Stefan-A]

If it's completely black, then it's not a T. sirtalis or a T. marcianus.

scaliger on the other hand does have a black tongue, as do all of the following species:

T. exsul
T. fulvus
T. godmani
T. mendax
T. nigronuchalis
T. rufipunctatus
T. scalaris
T. scaliger
T. sumichrasti