|MadSci Network: Botany|
Interesting question! Carnivorous plants like the Venus fly-trap still photosynthesize to make carbohydrates (thus they have green leaves), but they get their nitrogen fix from the insects that they trap, digest and absorb. This is due to the fact that these plants live in bogs, which tend to be low in available nitrogen. If the Venus fly-trap is grown in an environment where nitrogen is available in the soil, the plants can survive autonomously.
Thus said, I'm going into the grey-zone; the Venus fly-trap is a facultative heterotroph, as it can grow as an autotroph when in ideal conditions, and it can also get its necessary nutrients from other organisms in its typical habitat.
I've included the web site that I got the information from:
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