In the southeastern U. S., Spanish moss grows on trees, particularly along the coast and in the marshes. It can almost cover its host tree. Being an air plant, it only uses the tree for support.
Which type of species interaction is represented here?

The species interaction type that is represented here is commensalism.

Explanation:

In biology, commensalism is a non-mandatory interaction between two living beings in which one takes advantage of the nourishment or waste of the other without causing suffering or disturbance. One organism between the two (commensal) benefits from the other and the other is neither damaged nor helped (host). An example of this would be the relationship between pilot fishes and sharks, in which pilot fishes eat the remains of what the shark has previously hunted.

Other authors consider commensalism the sharing of the same environmental spaces in which to feed, even of the same food, without causing damage or reducing the nutritional possibilities of the other species. A brilliant example can be that of the cow and the goat, which feed on grass, both using the same lawn or space.