Botany Manor

In Chapter 2: Survivors of Adversity, you gain access into the Manor. The camera is located the lounge area which contains the harpsichord (another achievement).

You use this camera to assist the growth of the Fulguria. To get this achievement, you need to use the camera on any other plant.

Grab your plant (not Fulguria). Place it on the plate in front of the camera.
Grab your chemical flask (if used before, where you left it, if not it will be in the previous room with the chemicals on the shelf)
Fill the flask with Two Potassium and One Magnesium
Take your filled flask to the camera.
Use it on the tray, close the tray.
Take the picture
Achievement unlocked.

I used the Ash Plume which you have to grow in the same chapter. Another easy one would be the Windmill Wort you had to grow in the first Chapter.

Cheers!

I used the Ash Plume plant in Chapter 2 for this, once I'd grown it I took it back to the photo room and took a picture of it but you can use any plant as long as it's not the fulguria again.

The video will help you find all the clues along the way too needed for the Botanical Researcher Achievement.
This guide will walk you through all of the achievements and explain the solutions in under 2 hours, timestamps are below the video


ACHIEVEMENTS LIST TIMESTAMPS

0:00 – Intro
0:35 – Chapter 1
1:29 – Windmill Wort Achievement
3:55 – In the Bin & Green Thumbs Achievements
5:25 – Take a Break & Take a Nap Achievements
6:45 – Let me In! Achievement
7:45 – Quack Quack Achievement (Duck 1/5)
8:02 – Chapter 2
8:22 – Fulguria Achievement
12:38 – Boom Achievement
13:20 – Piano Woman Achievement
13:50 – Ash Plume & Crack Achievements
19:25 – Duck 2/5
19:50 – Photographer Achievement
21:50 – Chapter 3
22:32 – Pixie Tears Achievement
28:03 – History Sleuth Achievement & Art Lover (Painting 1/2)
33:20 – Duck 3/5
33:45 – Fixer Upper Achievement
35:25 – Wolfglove and Mountaineer Achievement
39:20 – Lockpicker Achievement
40:45 – Chapter 4
41:05 – Grandma’s Vault Achievement
43:12 – Sapphire Gloom Achievement
47:30 – Who Needs a Plumber & Clean and Tidy Achievements
51:16 – Some chapter 4 clues
55:26 – Duck 4/5
55:46 – Nightfall Achievement
58:41 – Cradle Fern Achievement
1:01:00 – Brook Chalice Achievement
1:04:50 – Chapter 5
1:05:48 – Art Lover Achievement (Painting 2/2)
1:07:00 – Frogger Achievement
1:08:04 – Some chapter 5 clues
1:13:32 – Quack Quack Quack Quack! Achievement (Duck 5/5)
1:14:05 – Help! And Achievement
1:14:55 – Oscilette Achievement
1:18:00 – Fools Emerald Achievement
1:21:31 – Springdance Shrub Achievement
1:28:10 – Botanical Researcher Achievement
1:28:56 – Flower Arranging Achievement
1:40:49 – The End Achievement

Once you start Chapter 2 and gain entry to the manor proper, this can be achieved.

Go and get your Windmill Wort flower and bring it with you all the way into the manor. Head into the room with the tree growing indoors, and take a right to the bottom of the stairs, then a left through the doorway. Go into the next room. Notice the chemical powders on your left. Continue through this room to the next one with the harpsichord in it.

On the wall at the back, near the writing bureau, is a plant pot stand with a camera set up facing it. Put your Windmill Wort down here.

Go back into the previous room with the chemical powders, and mix the following into the flask: Potassium, Potassium, Magnesium

Take the flask through to where you left your flower, and use it on the flash powder stand to the right of the camera, then close the powder tray. Now press the button on the table, and get your achievement!

Chapter 2

The camera is found in the family room and used to grow the Fulguria. But, you need to instead take any other fully grown plant and place it on the plate in front of the camera. Fill the flask in the previous room with two splashes Potassium and one splash Magnesium. Use this combination on the camera. Close it and take the picture.

Full video walkthrough including all achievements, puzzle solutions, and collectible locations! (Timestamps in YouTube Description)