Egg yolk flesh is yellow when it is ripe. Touch the fruit with your hands. If the fruit is soft, you can eat it

Egg yolk fruit (Latin name: LucumanervosaA. DC), also known as Xiantao, is a perennial plant of the genus Yolk in Caprifoliaceae. The tree is about 6 meters high, with alternate leaves, paper leaves, narrow oval, small white flowers, clustered in leaf axils.