scaleleaved

Scaleleaved is a botanical descriptor for plant leaves that are scale-like. The leaves are small, dry, and lack a broad lamina, appearing as narrow scales along the stem. They can be arranged in overlapping rows or in whorls around the axis, contributing to a scaly appearance on the plant. The term is used across both living plants and fossil taxa, but is especially common in the study of lycophytes and extinct Lepidodendrales, where the body of the plant is encased in decurrent, scale-like leaves.

In living plants, scale leaves may accompany more conspicuous leaves or microphylls; in some genera of Lycopodiophyta, the stem is covered with narrow scale leaves and only a few true leaves. In fossils, scale leaves provide diagnostic features for recognizing certain extinct forms; Lepidodendron, for example, is famous for its diamond-shaped leaf bases produced by overlapping scale leaves, used to identify the genus in Paleozoic coal deposits.

Discussions of scale leaves address questions of leaf evolution, morphology, and plant adaptation. The term emphasizes the reduction of leaf blade size and the modification of leaves into protective or moisture-conserving structures along the plant axis.