Helicoradium spirale

The helicoradian is a type of “sensitive zooplantae” that responds to touch by coiling up so that the single large leaf is no longer exposed to any herbivores that would eat it. Because it grows in clusters, the touch response, or thigmonasty, by one helicoradian often triggers the same response in others growing nearby so that the entire population recoils, one plant after another. This retraction is both defensive and an effective feeding mechanism to trap insects and small animals. (Read more)
Unseen contractile roots belowground aid in the retraction of each folded plant quickly into the ground. The reaction is so swift that it appears that the helicoradians are being sucked into the ground. The Na’vi are able to wander among the helicoradian without triggering this defense response, but are warned of the presence of danger when the plants start to react.

The large, beautiful leaf of the helicoradian is sometimes collected and used by the Na’vi, although they are careful not to over harvest this unusual life form and deplete its population. The brilliant orange pigment is extracted and used as paint, and the leaves are used for garments, tents, and sacks.