Discovering Hugo's Herbarium in A Plague Tale: Innocence
Starting in Chapter IV of A Plague Tale: Innocence, you can find a series of hidden flowers, all of which contribute an entry to your in-game Codex. Hugo doesn't necessarily have to be present in the stage for a collectible flower to show up, but if he is, you'll be able to tell when you've found a flower because Hugo will make a beeline for it. (No pun intended.)
Finding a flower also results in Amicia wearing a blossom in her hair for the rest of the current level.
Collecting half of the flowers in the game unlocks the Herbalist trophy/achievement. Once you've found them all, you receive the Botanist trophy/achievement.
Discussing the collectibles in A Plague Tale will involve unavoidable mild spoilers. Please do not read further until you've had a chance to clear the game for yourself. Once you've completed a stage, you can revisit it from the chapter selection menu at any time.
Note that any collectible you find in A Plague Tale is saved to your profile on the spot. Even if you die after finding it or quit out of the game, the collectible item is still saved in your Codex. You can pick it up again on subsequent attempts or runs through the game, but all you have to do is grab it once.
Flower Locations in A Plague Tale Innocence
When Hugo finds flowers in the courtyard of the church in Chapter III, stop to inspect the plant he's looking at. You can technically skip this if you move on without interacting with Hugo, but it's otherwise difficult to miss.
Once you get through the fields to the farm in Chapter IV, go all the way to the back of the lot, between the farmhouse and the back fence. You're looking for a little purple flower at the base of a tree.
At the start of Chapter V, before you get to the battlefield, keep an eye on the left side of the path. You can see this flower well before you can reach it, growing on a ledge that overlooks the path.
Once you've caught up to Hugo, keep an eye on your left. You can follow the hillside up a bit at one point to find a well-hidden alchemists' chest. Keep going past it to follow the path back around to the flowers.
In Chapter VII, when you reach the ruined village that Melie says is cursed, don't follow her to the left right away. Instead, go right and look behind the fallen wall at the end of the path. Hugo will find a bush.
5: St. John's wort
After the scene with the tree at the end of Chapter VIII, before you go to talk to Melie, look at the plant Hugo's playing with.
Right at the start of Chapter IX, keep an eye on the left side of the path as you follow Melie.
In Chapter X, in the university library, make progress until the point where you have to unleash a rat swarm on a couple of armored guards. Once the rats have fully left the alcove they've been sealed up in, investigate it to find this flower growing out of the floor. Somehow.
Before you go to talk to Lucas in Chapter XI, take a right and go along the outside edge of the courtyard. You're looking for these flowers, in an easy-to-spot bush.
Once you emerge from the castle after visiting Hugo's room in Chapter XII, hang a left before you go down the stairs and look for this flower, on the ground next to a deformed statue.
After you rescue Hugo in Chapter XIII, keep an eye on your right as you go down the path. You can find this flower in a small clearing there.
This is an easy flower to find, as there's only one place in all of Chapter XIV where a flower could theoretically be growing. The problem is that it's in the courtyard, which is crawling with Inquisition guards.
While you're following Nicholas, he'll pause to talk to a couple of people in the courtyard. When he leaves, don't follow him right away. Instead, dodge the guards and work your way around to your left, to the hedges on the far right-hand side of the courtyard. The berries are growing on a small bush inside it.
Right at the start of Chapter XV, talk to Lucas, then open the door near him and walk through. The flowers are at the other end of the room, next to the bench.
13: Christmas rose
Progress through Chapter XVI until you reach the part where Rodric has to break into the burning house for you. Fend off the guards, then use the door they came in through to reach a yard on the other side of the chasm. Hugo will present Amicia with "her flower."
If you need a hand finding the other collectible items in A Plague Tale, check out our guides to the Curiosities and Gifts. If you're still on the fence about whether or not to play the game, you can also head over and read our full review.