"Probably a couple of hours, all condensed," Severus answered with a shrug. "I keep adding new things as I find them, and I'll make a point to pass them along to you from now on."
He reached over to the pile of things he had stacked next to him on the table to retrieve his Charms notes. After unrolling the parchment, and sticking a book over the top end to hold the roll in place, he cleared his throat.
"So ... belladonna -- see also deadly nightshade, on page ... seventy-six, I believe." He added the last bit with a smirk. "Did you understand the bit about why dragon dung isn't a suitable fertilizer?"