Xingchen hums softly, then considers, trying to recall.

"Some varieties of them were made into pills along with other ingredients, I think mostly to prevent blood clotting that can lead to some stuck inside the veins.

"My knowledge is therefore not very extensive - I was focusing more on ways to help the blood stop flowing, rather than the other way around."

An embarrassed small smile that he can't help too much.

His teacher probably knows, but he left her too early to learn all. Or even most.