The Dragon's Roar of the Nine Heavens

“Xinghe, you have an excellent memory. Ordinary seven-star grass is indeed pure green, but this one grew in a crack on the shady side of a rock and absorbed moonlight for a hundred years. Its medicinal properties mutated, making it top grade. One of these is worth a hundred ordinary ones.” Chu Mingyuan spoke gently and patted his son's shoulder. “When we get back, I'll teach you how to use it to make Concentration Powder. It'll help scholars remember everything they read at a glance.”