Botanically, the most interesting phenomenon of the Sueve is the ancient yew forest on its northern slopes. Widely regarded as the largest remaining yew forest in Europe, it covers some 80 hectares and isformed of over 8,000 yew trees, many of which are over 1,000 yearsold (data from "Amigos del Texu"). There have been calls for the forest to receive increased protection, and even for all the yew trees in the north of the Iberian Peninsula to be collectively awarded UNESCO World Heritage status. Since the introduction of fallow deer to the Sueve in 1960, the yews have not been able to regenerate effectively, which is a cause of concern. The forest is an extensive area of individuals and pockets of yews, intermixed with clearings and other tree species. It is obvious to the observer thatthe yews are pushing the boundaries of their comfort zone, living on thin limestone soil on an exposed mountain side.

Another woodland of note is the Sueve's only beech forest, which is unusualin growing on a south-east-facing slope, at 500 to 900m altitude (the area's beech forests occur almost exclusively on north-facingslopes above 800m). The forest is called La Biescona, and is situated on the opposite hillside (on your right) when walking from the Fito viewpoint to the pastures of Bustaco. Other tree cover includes both eucalyptus andpine plantations (the pines most notable around the old refuge abovethe Fito viewpoint).

The rest of the Sueve is predominantly mountain pasture. At the foot of the slopes, flower-rich hay-meadows, pastures and croplands dominate, with the addition of monocrop eucalyptus plantations. Above these are oak, birch, alder, chestnut, ash, and other broad leaved tree species characteristic of the coline zone,interspersed with heathers (including bell heather and St. Dabeoc'sheath), gorse, greenweeds (Genistaspp.),and ferns. Above 500m the mountain pastures dominate, mingled with hollies and hawthorns, often standing as individuals shaped by the wind. Year-round grazing pressure has moulded the vegetation of the mountain pastures, leaving a closely cropped sward, spattered with wild flowers such as chamomile, wild narcissus (Narcissus asturiensis),clustered bellflower, the Merendera montanalily, violet, primrose, butterwort, milkwort, foxgloves, globethistle, field eryngo (Eryngium bourgatii),and species of toadflax.