Pteris lidgatei, a member of the maidenhair fern family (Adiantaceae), is a coarse herb, 0.5 to 1 m (1.6 to 3.3 ft) tall. It has a horizontal rhizome 1.5 cm (0.6 in) thick and at least 10 cm (3.9 in) long when mature. The fronds, including the leaf stalks, are 60 to 95 cm (24 to 37 in) long and 20 to 45 cm (8 to 18 in) wide. The leafy portion of the frond is oblong-deltoid to broadly ovate-deltoid, thick, brittle, and dark gray-green. The sori are apparently marginal in position, either fused into long linear sori, or more typically separated into distinct shorter sori, with intermediate conditions being common. Pteris lidgatei can be distinguished from other species of Pteris in Hawaii by the texture of its fronds and the tendency of the sori along the leaf margins to be broken into short segments instead of being fused into continuous marginal sori.