Fallen leaves and other plant material that lies on the surface of the ground and decomposes to form organic matter. This can then be used by the plants as nutrient.

a layer of decaying plant matter (such as leaves, twigs, grasses, etc.) found on top of the soil

Dead leaves, bits of bark, and other dead plant matter. Leaf litter is the main shelter for many small animals, including insects, centipedes, and isopods.

The layer of fallen leaves on the forest floor.

The leaves that have fallen from a plant, either through normal seasonal changes or due to disease. Especially in the latter case, leaf litter can harbor pathogens and should be cleaned up promptly, particularly around plants such as roses. In a naturalized, woodland setting, leaf litter can be a normal part of the workings of the garden.