What details should a photo include for a plant to be identifiable?

Most identification failures come down to missing information rather than image quality. A sharp close-up of one leaf is often less useful than a mediocre photo showing the whole plant, because habit and growth pattern narrow the field faster than leaf shape does.

Include four shots where you can. A whole-plant view showing overall shape and how it holds itself. The upper surface of a typical leaf, laid flat, with something for scale — a coin or a fingertip. The underside of that same leaf, which carries diagnostic detail such as venation, hairs and colour that the top does not. And a close view of the stem where a leaf joins it, since the arrangement of leaves around the stem, the presence of a sheath, and whether stems are round or grooved are strongly diagnostic.

Add flowers or fruit if there are any. They outrank everything else — many genera are separated on floral structure and are genuinely ambiguous from foliage alone.

Context helps as much as anatomy. Say where it is growing, indoors or out, in which country and climate, whether it was bought or appeared on its own, how tall it is, and whether it is woody or soft-stemmed. A succulent rosette in a Mediterranean garden and the same rosette on a windowsill in Norway lead to different answers.

Shoot in bright indirect daylight rather than under artificial light, which shifts colour badly. Avoid flash, which flattens texture and blows out leaf surfaces.

Finally, treat any identification — from a person or from an app — as provisional until you have checked it against a description. Never eat, brew or medicate with a plant on the strength of a photo match.