Dunderbush is a plant appearing in Dragons: Rescue Riders.
Although the whole Dunderbush plant is never seen, it is most likely a type of bush, judging by its name. The leaves are large, having five lobes, their shape resembling a star.
Dunderbush is edible to dragons, mainly Slobber Smelters.
After the Rescue Riders helped Grumblegard reclaim his island in "Grumblegard, Part 2", the Foreverhorn returned the favor by helping the Riders take care of dragon hatchlings. He brought a sack of plants to The Roost, containing Speckled Spice Pepper and Dunderbush. Leyla picked up a Dunderbush leaf from the sack and Grumblegard explained that it was one of Slobber Smelters' favorite food. To prove his point, Sizzle and his siblings jumped into the sack and devoured the leaves.