Ponga Natural Park has an altitude range from 220m at Sellaño to 2141m on the summit of Peña Ten. This can be referredto as three vegetation belts - coline (up to 800m), montane (800 to1800m), and subalpine (1800m and above). One of the park's most important features is the extent of mature forest cover, which has been measured at 37% of total land area.

The coline habitat has a climax vegetation of mixed deciduous woodland, composed of species such as sycamore, alder, ash, chestnut (with traditional areas of coppiced chestnuts), bay, lime and hazel. Where humans have cleared the forest to provide fodder and grazing for farm animals,there are meadows of wildflowers, which are at their most colourful and interesting in late spring and early summer, before the hayharvest.

The montane habitat in Ponga Natural Park is dominated by beech forest. The most extensive of these forests is Peloño, covering 1500 hectares, regarded as one of the best preserved beech forests on theIberian Peninsula, and already protected by law prior to Ponga being declared a natural park. Accompanying the beech are sessile oak, Iberian white birch (Betulaceltiberica),holly (sometimes in pure stands), rowan, whitebeam, willow, hazel andhawthorn.

The forest floor sports an abundance of heather, blueberries, mosses, lichens, and fungi. Interspersed amongst the forest of the montane belt are the high pastures of traditional farming, where an array of flora species can be found, including thedog's tooth violet, petticoat narcissus, Narcissus leonensis,the multi-headed Narcissustriandrus (upto 1000m altitude), elderflower orchid, burnt-tip orchid, greatyellow gentian, and the Pyrenean snakeshead fritillary.

Only the tips of the highest mountains in the park can be regarded assubalpine habitat, with hardy species clinging to life amongst therocks.