Rainforest is a high diversity ecosystem; there's a lot of green out there and most of the plants have the same problem of making your presence known. Since individuals plants are at a low density, the plant must have a means of signaling their presence to pollen dispersers who must then move to the next individual of the same species if pollination is to be achieved. Plants whose flowers are small have to find ways to advertising and one strategy employed by quite a few is to group small flowers together and put something big, gaudy, and colorful right next to them, usually a modified leaf, a bract. This plant (Warszewiczia coccinea) is called the wild poinsettia but it is a member of the coffee family (Rubiaceae) not the euphorb family of the true poinsettia, which is another neotropical plant. That's the trouble with common names; you just can't trust them. But they do both use this mechanism of placing a bright red bract next to a cluster of small rather nondescript flowers, so you don't miss this one out in the forest.