A visiting botanist at the Bosque once told me that plants have a way of tricking their predators. One way of deceiving an insect looking for a juicy tender meal of new leaves is to camouflage them in different colors. Grasshoppers, ants and other consumers of forest salads are evidently tuned into green, not other colors. The ingá plant in the image is a good example of trickery. In the background you can see its older mature leaves, all green. The new leaves in the foreground are brightly colored, thus giving them a chance of survival until they toughen up.
Another way some plants increase their chances of survival is to form contracts with potential enemies. What could be better than a delicious new leaf? Honey, of course. Enter extra-floral nectaries. In the case of the ingá plant, they are located at the conjunction of leaves. The nectar attract certain ants, which get a good easy meal and in return, they protect the plant from the leaf-eaters. A symbiotic relationship, the biologists call it.
There are many different species of ingá. The genus is also called Inga, without the accent mark.