Plants: large, in loose or occasionally compact tufts, bright green to yellowish, brownish proximally. Stems: 4–8 cm, erect, simple, tomentose proximally. Leaves: not or rarely seriate or spiraled, appressed on sterile and female stems, secund when dry, erect-spreading to falcate spreading when moist, ovate-lanceolate to lanceolate, 1.3–3 mm; margins revolute, serrulate nearly throughout, teeth paired on mature leaves; apex evenly and gradually acuminate; costa subpercurrent to short-excurrent, 600 µm wide at base, distal abaxial surface weakly prorulose; laminal cells prorulose at proximal ends; basal cells rectangular, shorter, broader than distal; juxtacostal cells at widest part of leaf 48–100 µm; distal cells linear, 20–40 × 3–5 µm. : Specialized asexual reproduction absent. Sexual: condition dioicous; perigonia discoid. Seta: 4 cm, straight or flexuose. Capsule: 2–3.5 mm. Spores: subreniform, 22–25 µm.
Moist areas. low to moderate elevations. Greenland, Europe, Asia, Africa.
Philonotis calcarea is a member of the P. fontana complex; it is essentially an Old World species that enters the flora area only in southern Greenland. Its distinguishing features include falcate-secund, plicate leaves, very stout costa, and lax, pellucid, and quite large juxtacostal cells.