Montane, mossy Pinus sylvestris forests of the Pyrenees; characteristic of regions with a moderately dry, sunny climate, they occur, at all exposures but mostly on ubacs (north facing slopes), in a wide belt on the south flank of the range, with limited outposts on the north flank. Characteristic is the abundance of wintergreens (Pyrola chlorantha, Pyrola minor, Moneses uniflora, Orthilia secunda) and of mosses (Hylocomium splendens, Rhytidiadelphus triquetrus, Pleurozium schreberi); Vaccinium myrtillus, Luzula nivea, Hepatica nobilis are usually present.
Silicicolous formations of Pinus sylvestris with Sorbus aucuparia, Salix caprea, Calluna vulgaris, Galium rotundifolium, Melampyrum sylvaticum, Melampyrum pratense, Lathyrus linifolius (Lathyrus montanus), Potentilla erecta, Helleborus viridis ssp. occidentalis, Deschampsia flexuosa.