The bog asphodel is a rare plant found on wet, acidic, and low-nutrient peat bogs and moorlands.
Like the marsh gentian, this plant is on the Red List of Threatened Species but thrives in the park nonetheless.
A huge population of bog asphodel can be found near the IJzeren Man. This plant is part of the Liliaceae family. It is a 10 to 30 cm perennial with bright yellow flowers. Flowering in great numbers from June to the end of August makes the species hard to miss. The same is true in the autumn, when it bears striking orange-red fruits.
Eating the plant was long thought to cause sheep to develop brittle bones. A possible explanation for this is that the plant exclusively grows in acidic soil with little to no calcium, a substance necessary for strong bones. Bog asphodel also grows in moist soil, which makes it easy for sheep to get stuck.