The high fells aren't just a massive adventure playground - many of them, like High Spy are also Sites of Special Scientific Interest (SSSI) because of their interesting collections of unusual alpine plants. When placing the cache I noticed an abundance of the alpine variety of lady's mantle Alchemilla alpina on and around the path.
Other unusual plants that it's always a joy to spot are the insectivorous plants like butterwort Pinguicula vulgaris also poetically known as bog violet because of its purple flowers that grow out of a star-fish-like base of pale green leaves. The leaves trap insects and digest them, gathering nutrients where the soil is too poor to provide them.