my (beginners) understanding of landscape photos is that you generally want them to be with a wide-angle lens

My understanding of landscape photos is that they should contain some landscape! I can understand the association with wide angle lenses, though. You typically want to get a lot in, a photo of a rock is not a landscape photo.

Any focal length can be used, the key is that if you use a long lens, the subject is far enough away that you still get a lot of landscape in. Here's is an example of this (note I'm not claiming this is a "great" landscape photograph ;)

This was shot from the top of Mount Snowdon, the ridge and background hills were a long long way away. The telephoto creates a different composition and compresses the scene.

• You do need good atmospheric conditions to take telephoto landscape shots, fog, haze, heat-haze and other effects that might not show up in a wide shot can seriously degrade sharpness and contrast.

The temptation when getting into landscape photography is to go as wide as you can. This is perhaps motivated by seeing panoramic format images with a wide field of view. However it can actually be difficult to get results if your lens is too wide. You end up with vast amounts of foreground and structures in the distance shrunk down.

Better results can often be obtained by shooting a medium focal length and cropping to a wide format to give the impression of a wide field of view.