Lost in Translation?

Has anyone else ever wondered why Tree pose is called Tadasana in Bikram yoga?

I am constantly confused by this.  I asked a teacher once and she told me that the way it was explained to her was that it is because Bikram is from Kolkata, which is in the east of India and Iyengar and Patthabi Jois are from Pune and Mysore which are more to the west of the country and therefore the dialect is different.

The way I was originally taught, Tadasana is Mountain pose which could also be similar to Samasthitti.  While practicing Iyengar yoga, I learned that Vrkasana is the Sanskrit word for Tree pose.  I know that Tree pose in Bikram is more similar to Half Lotus Bound pose or Ardha Baddha Padmottanhasana in Ashtanga yoga than to the traditional Tree pose.   And that Ardha Baddha Padmottanhasana looks like the 1st and 2nd stage of Toe Stand or Padangustasana in Bikram.  And when you Google Padangusthasana (with the H inserted) your results are any asana that have the word "big toe" in it.

I think I may have opened a huge can of worms, which probably has no straight answer.  It may simply be a case of the definition of a word from Sanskrit to English being lost in translation and modified along the way.

If anyone has any ideas on this, I would love to hear from you. 

Vrkasana or Tree pose. Via

Bikram's Tadasana or Tree pose. Via

Ardha Baddha Padmottanhasana or Half-lotus Bound into Standing Forward Bend. Via