4. Orthothecium strictum Lorentz, Moosstudien. 122, plate 5, fig. D. 1864.
Orthothecium binervulum Molendo
Plants small, in tufts, orange. Stems 1-6 cm, 0.5 mm wide, erect to ascending, sparingly branched. Leaves erect-imbricate, straight, ovate-lanceolate, not to slightly plicate, 1 mm; margins partially recurved, serrulate distally; apex short, flexuose, subhyaline; costa double, short; basal laminal cells shorter than medial cells, brownish yellow; medial cells oblong-linear, 48- 64 × 8 µm. Specialized asexual reproduction rare, by clusters of propagula in leaf axils, claviform, multicellular. Sporophytes unknown.
Moist tundra, humus, soil, rock ledges, crevices; low to high elevations (10-2800 m); Alta., B.C., Man., Nfld. and Labr. (Nfld.), N.W.T., N.S., Nunavut, Que., Yukon; Alaska, Colo.; Europe.
Orthothecium strictum is distinguished by stems0.5 mm wide and 1-6 cm long, and the indistinctly plicate, erect-imbricate, narrowly lanceolate leaves with revolute margins, ending in a short, flexuose, subhyaline acumination. The perichaetial leaves are ovate-lanceolate. A single collection (Alaska, Steere 18846, NY) had claviform multicellular propagula present in axils of leaves.