The leaf detective: an autumn walk with a mission and a herbarium

An autumn walk announced as an autumn walk lasts eleven minutes and ends with somebody asking how much further. Announced as a detective mission it turns into something else: evidence has to be found, every piece of evidence is a leaf, and the suspect is the tree it fell from. Suddenly the child who wanted to go home is three metres ahead, scanning the ground.

The whole plan fits into one afternoon: collect leaves on the walk, photograph them, ask the AI which tree they came from, check the answer, and build a herbarium at home with one page per tree. Each page carries three things: the leaf, the name of the tree and one astonishing fact the child prised out of the AI. After two walks there is a booklet worth showing to a grandparent.

• A paper bag, never plastic: wet leaves go mouldy in plastic within a day.
• One leaf per tree, not twenty from the same one. The herbarium is a collection of trees, not of leaves.
• Photograph the leaf on a plain background, and if you can, photograph the bark and the whole tree too: that lifts the hit rate a lot.
• A notebook recording where each leaf was found. The location is part of the evidence.

I am [AGE] years old and I am making an autumn herbarium. I am showing you a photo of a leaf I found in [PLACE OR REGION]. Name the three most likely trees, not just one, and rank them by how confident you are. For each one, explain how I can recognise it myself: leaf shape, edge, bark, fruit. Finish by telling me what I should go and look at on the real tree to decide between your three options.

The herbarium page

The leaves go between two sheets of newspaper under a stack of books for three or four days. After that they are taped down at the edges on a sheet of paper, with the tree name, the date and the place written next to them, and a gap left for the astonishing fact. That gap is the reason the child goes back to the chat voluntarily.

I found out that my leaf comes from a [TREE]. Tell me three astonishing things about this tree that a [AGE] year old would find amazing, one sentence each. For each one, tell me whether it is established knowledge or more of a story, and where I could look it up. If you are not sure about something, I would rather you said so.