Morten St George Theory

[-JKP-]

So it's not as simple as saying they are heliotropic. They don't "follow" the sun. They are facing east before the sun comes up.

Don't look up the Spanish name jkp, that would really about you. 
They are called girasoles - lit. Turners toward the sun.

LOL!!  

It might be more accurate to call them "sun anticipators" maybe something like preverisoles.  Except then you have to get in the part about them turning at night, as well. Hmmm, that could get complicated.