I'm also on the Too Hot To Handle Substory, though before Almaria because I want to beat the bosses before I miss the hidden boss there.
No matter where I look in Myrtle Forest, I cannot find any ingredients. Nothing is "shining" on the ground, nothing dropped by mobs, even the hidden boss doesn't have it. Help us No-Budget! You're our only hope!
EDIT: After the v1.11 update, I'm able to find the stuff.