Stems 2-2.5 cm, green or yellowish green, branches curved at apices. Leaves homomallous, 0.8-1.3(-1.5) mm; margins reflexed at base, entire or serrulate at apex; apex abruptly slender-acuminate, not subulate; alar cells quadrate-rectangular, walls thick, region extending 1/4-1/3 leaf margin; distal laminal cells 25-35 × 4-7 µm, walls thick. Seta yellow-orange, 1-1.6 cm. Capsule yellowish to reddish, 1-1.7 mm. Spores 11-20 µm, minutely papillose.

Varieties 2 (2 in the flora): w United States, Mexico, Asia, Australia.

Homomallium mexicanum is a largely subtropical species that appears more robust than the other two North American species of Homomallium because of its larger and more spreading leaves.