ANGUSTIFOLIUM-PEAT (EN: angustifolium peat; DE: Angustipholium-Torf; FR: angustipholium tourbe; ES: angustifolium turba; RU: ангустифолиум-торф) is the type of the raised-bog peat, which is containing among the plant residues at least 70% of the sphagnum mosses, of which the remnants of the Sphagnum angustipholium constitute more than half; there are among other residues the cotton grass, scheuchzeria, heath shrubs, and unique residues of other grasses.

The angustifolium-peat is formed within the places of the intensively watered sphagnum (cotton grass with sphagnum or scheuchzeria with sphagnum) swamps, mainly at the peripheries or within the central flat tree-less places of the raised bogs.

The angustifolium-peat is commonly embedded from the surface down to the depth of 1.5 metres, or in the form of layers. The depositions with predominance if the angustifolium-peat may be found mainly within Siberia and the Far East. The ratio of decomposition of the angustifolium-peat is from 5 to 25%, the humidity is 92-94%, the content of moisture is 12-27 kilogram per kilogram, the content of ash is 1.5 (within the European part of the USSR) and 5.0% (Siberia and Far East), the average composition of the ash (%): SiO2 is 45, CaO is 22, Fe2O3 is 7, Al2O3 is 7, SiO3 is 8, P2O5 is 3. After the drying of the milled peat (to 40%), the content of moisture is decreasing to 8.2 kilogram per kilogram.

The depositions with predominance of the angustifolium-peat are developed for the production of the bedding, insulation, and packaging materials, and also for the obtainment of the fodder yeast, alcohol, and other products.