Stereodon obtusifolius Mitten, J. Linn. Soc., Bot. 8: 42. 1864

Plants medium-sized to large, in moderately loose mats, green to golden green. Stems to 15 cm, leafy shoots 0.7-1.3 mm wide, branches julaceous. Stem leaves closely imbricate, broadly ovate to ovate-oblong, 1.1-1.5 × 0.6-0.9(-1.3) mm; margins slightly serrulate, often appearing entire due to incurved margins; apex abruptly narrowed, obtuse or shortly apiculate; costal terminal spine absent; alar cells quadrate to short-rectangular, 10-15 × 10-12µm, walls moderately thick, region small, indistinctly delimited; laminal cells 40-65 × 5-6 µm; basal juxtacostal cells elongate, 10-25 × 5-7 µm. Seta 1-1.5 cm, strongly roughened throughout. Capsule inclined. Spores 10- 16 µm.

Rock and soil in wet places, temporarily submerged, along streams and small creek banks; low to high elevations (0-2700 m); B.C.; Alaska, Ariz., Calif., Idaho, Mont., Nev., Oreg., Utah, Wash.

The elongate basal juxtacostal cells and strongly tumid habit of Scleropodium obtusifolium are similar to S. touretii, to which this species is related. Leaf apices are obtuse in S. obtusifolium, but under a stereomicroscope or hand lens they may appear somewhat pointed. In S. touretii, the acumen is at least several cells in length, whereas leaves of S. obtusifolium lack an acumen. The stems are sometimes floating; the branches are tumid and often arching.