Red Cacao Leaf Nodes

[Vachtra]

I have 6 cacao trees growing right now and one of them has always had red nodes at the base of the leaves and at the point where the leaf stem connects to the tree. Anyone know why thins might be? The rest don't do this except for one which is very infrequent.
Does anyone know if this is a species variation or if this is a reaction to something?

 

[Marck]

Growing Cacao (Theobroma cacao) sounds like a fun endeavor. With time and ample light, warmth, and humidity you may get pods one day. Of course the seeds are used to make chocolate, but the pulp of the fruit is also sweet and refreshing. I expect the red pigment on the petioles is a variable trait. It seems to appear consistently on one individual and only sparingly on another, perhaps due to higher light exposure.