Thorns are small plant live. With different ways to sustain itself depending on the thorns present in close proximity.
Once a plant has collected enough energy, it will sprout a seed and eject it closely.
This plants absorb the magical energy in the sand, Once there is sufficient thorns are in proximity the plants can create an energy vine capable of leeching any energy source. The more Thorn plants are around and the bigger the specimens are, bigger the targets they can in-tangle and leech. This ranges from Skippers, Gliders to ships and more !
The plant does not seem to have any size limit, if it can feed enough, it shall grow and multiply. If left unchecked, they will control large areas and make them nearly impassible.
Some Dysnomians have managed to domesticate and farm Thorn plants, their juices are used in flask and diverse medical processes. There is however no point hunting the smaller thorn plants for their cores : Harvesting or destroying the small plants destroyed the core with them. It is, on the other hand possible on the bigger plants.
Their cores usually give a bonuses to harpoons and range, at the cost of mobility or speed.