Last week I was looking for images of Cystopteris alpina spores on the internet, and couldn’t find any on a couple of Google searches. Fortunately a plant of Cystopteris alpina in the greenhouse had some mature spores, so I was able to create my own images. These are taken at x 1,000 magnification – when the depth of field is very small. This means that either the projections around the spores are in focus, or the surface of the spore is in focus. What surprised me a bit was the very pronounced linear projection on the ‘inner’ curve of the bean-shaped spores. This is only visible if the spore is in the right orientation, and it seems to be quite variable.