"To the Yew Tree Above Dafydd ap Gwilym's Grave" (Welsh: Yr Ywen uwchben Bedd Dafydd ap Gwilym) is a 14th-century Welsh-language poem in the form of a cywydd, and is usually seen as either an elegy written after the death of Dafydd ap Gwilym or a mock-elegy addressed to him during his lifetime. Its author, Gruffudd Gryg, also wrote another elegy or mock-elegy on his friend Dafydd, and conducted a controversy in verse with him in which Dafydd's poems were criticised and defended. The cywydd on the yew tree constitutes the main evidence for the widespread belief that Dafydd is buried at Strata Florida Abbey (also known as Ystrad Fflur) in Ceredigion. It has been called "a superb poem, perhaps Gruffudd Gryg's best...a remarkably sensitive and perceptive act of poetic homage that acknowledges,
