Parallel venation occurs in dicot
Corymbium
Parallel venation means the veins present within the leaves are arranged parallel to each other. These veins never join any other veins. No branching is seen in parallel venation. All the monocots are parallelly venated whereas the dicots have reticulate venation except Corymbium and Calophyllum which are parallelly venated. So, the correct answer is 'Corymbium'.