Belkzen brambles

Belkzen brambles are a thorny plant that appears to be dead when viewed from a distance, but are very much alive and very sharp. The wood is of a black color, and the sap appears to have to consistency of oil. The brambles themselves are actually seed-pods with pointy protrusions which catch on passing animals or people. Those who know how can actually harness the sharp brambles and turn them into quite effective improvised caltrops.