Subject: Are philodendrons really scototropic?

Is it true that philodendron seedlings in the jungle seek the trunks of trees 
by growing toward the DARK? I read this somewhere, and the source was emphatic 
that they were not growing AWAY from light but TOWARD the dark. This does not 
seem possible since darkeness is like a vacuum - the absence of something 
rather than a physical property. Experiments were supposedly done where the 
highest light intensity was at 90 degrees to the area of least light intensity 
and the plant grew directly toward the dark spot. Can this be true? Also, 
supposedly, this ‘scototropism’ reverts to normal phototropism after the 
philodendrons climb the tree trunks the reach the canopy  of the forest. What 
is the explanation for this behavior?

Re: Are philodendrons really scototropic?