You can fairly easily propagate them from stem cuttings, but not from the root alone. In you original picture, the stem is along the top center of the pic - what the leaf petioles are directly attached to. All of the long, thin, brown (almost rope-like) strands that are coming out and coiled on the tabletop next to the red pot are the air roots. In nature these are for stabilization as well as nutrient absorption, but new plants cannot be started from just those roots themselves. A portion of the stem must be attached.
