Bull. Torrey Bot. Club 22: 42. 227. 1895,.
Stem leaves 3–3.5(–4) × 1–1.3 mm, margins multistratose throughout except 2-stratose at apex (pseudocosta in cross section with chlorophyllose outer epidermal cells and small, thick-walled inner cells), toothed or entire; basal; laminal cells rectangular to quadrate, 15–40 × 7–10 µm, juxtacostal cells shorter; medial and distal laminal cells 10–15(–18) µm; marginal laminal cells with stereid cells 150–200 µm. Peristome absent.
Habitat: Exposed to submerged in streams or rivers, rocks, particularly granitic
Elevation: moderate to high elevations (1000-1800 m)
B.C., Calif., Idaho, Mont., Oreg., Wash.