Shadow Spurs is flora in Avatar: Frontiers of Pandora, and is most commonly found growing near water in the Kinglor Forest. Shadow Spurs have long, branching stems that each result in a single seed pod, wrapped in claw-like leaves.
As these bulbous pods ripen, they slowly fill with gasses drawn from the soil and are produced as byproducts of feeding. When the pod is fully mature, the leaves wither and unhook from the slightly lighter-than-air seed pod, which allows it to float into the atmosphere. Once high enough, the relative internal pressure of the gasses in the pod becomes too great and it explodes, spreading the seeds far and wide.
These floating seed pods are fragile and often don't get too high off the ground. Hitting another plant or animal causes them to burst, dropping their light seeds which form a dusty cloud on the ground. This cloud is toxic to some wildlife.
Shadow spurs can be found throughout rainforest regions, favouring sheltered and warm conditions. Although they have been found growing in other biomes throughout the Western Frontier, they are likely found further afield, given their method of seed dispersal.
Na'vi have found a number of uses for the seeds of the shadow spur. These include being ground into spice, and as decorative beads that can be threaded and woven into garments.
Harvesting a floating pod is considered a test for Na'vi archers; tracking the shadows of the floating po, shooting them out of the air, and then making sure to not be hit by the falling pod. Fortunately for the Na'vi who need to quickly gather the seeds before they're lost on the breeze, the toxin contained within the seed pods dispurses quickly before doing significant harm.