Hookeria radiculosa Hooker, Musci Exot. 1: plate 51. 1818; Hypnum wrightii (Sullivant) Sullivant; Omalia wrightii Sullivant; Pterygophyllum indicum Bélanger; Stereophyllum indicum (Bélanger) Mitten; S. radiculosulum (Müller Hal.) A. Jaeger; S. wrightii (Sullivant) Renauld & Cardot

Stems 3 cm, 1-2 mm wide across leafy stem. Leaves 1-2.5 × 0.4-1.2 mm; costa bulging abaxially; alar cells 9-19 × 9-14 µm, many on one side of costa and few on other; distal laminal cells 14-38 × 7-9 µm. Perichaetia with leaf margins serrulate, especially distally, proximal laminal cells smooth, walls thin, distal cell walls thick. Seta 0.6-1.2 cm. Capsule 0.7-1.8 mm; operculum 0.5-0.7 mm.

Capsules mature winter. Oak woods, swamps, base of trees, exposed roots, stumps, logs, limestone; low elevations (0-100 m); Ala., Fla., Tex.; Mexico; West Indies; Central America; South America; Asia; Africa; Australia.

Stereophyllum radiculosum is recognized by its dull, complanate-foliate plants with simple or sparingly branched stems; leaves with a single prominent costa that bulges on the abaxial surface; abruptly acute to obtuse leaf apices; and short, rhomboidal laminal cells, usually with a single papilla over the lumina on both surfaces of the leaves.