A phyllome that is reduced in size relative to a vascular leaf on the same plant and is often associated with a perennating or dormant bud or a vegetatively propagating organ such as a rhizome. [source: ISBN:0080374913]
Comment
May be photosynthetic or non-photosynthetic. Some species have vascular leaves that are scale-like (such as Juniperus, Thuja, and Chamaecyparis). Annotations for scale-like leaves should go under vascular leaf (PO:0009025), not scale leaf.