The Sierra de Guadarrama presents a high floristic diversity favored by multiple factors, related mainly with their geographical location. This position has allowed the existence of transitional characteristics between the Mediterranean and the Euro-Siberian regions. In that sense, the Sierra de Guadarrama has acted as a refuge for colder environments which had a wider distribution in the past and have disappeared from the neighboring territories.
In addition, the defendant altitudinal gradient of the Sierra de Guadarrama generates a high variability of climatic factors and soil in a relatively small area of land, which results in the existence of a large number of habitats. Their isolation, as a major mountain range in the heart of the Castilian plateau, has led to significant processes of endemicity.
Although there are no definitive studies that allow us to calculate exactly the number of vascular plants that inhabit in the area of the National Park, approximately there are about 1,680 taxa between species and subspecies.
Most of these taxa corresponds to angiosperms, the dicotyledons (over 75%), monocotyledons (around 20%) have lower representation, and a small number of gymnosperms and Pteridophytes. About more than half of the world's flora is made up of herbaceous perennials, around 30% by annual herbaceous, around 15% by trees and shrubs, and almost 4% by species related to the aquatic environment.
The National Park flora contains, for the most part, representative taxa of flora and vegetation from the Mediterranean high and mid-range mountains ecosystems. Due to the location of these mountains in the central area of the Iberian Peninsula, the territory receives a notable Northern influence, especially in the high areas and valleys toward the north. There is therefore a significant finicola flora component, that is to say, species which have their optimum distribution on the European continent and reach the Central System, having their southern limit of distribution in these mountains or in other Iberian mountain ranges. Examples of these species are Epilobium angustifolium, Eryngium bourgatii, Fraxinus excelsior, Gentiana lutea, Paris quadrifolia, Phyteuma hemisphaericum, Quercus petraea, Ulmus glabra, Vaccinium myrtillus, etc.
Another very important floristic element in the National Park flora is the endemic element, made up mainly of wallflower Iberian endemism, some of them exclusive to the Central System and a few limited to the Sierra de Guadarrama Mountains and adjacent mountains. Among these endemic species we can mention some very representative of the Sierra de Guadarrama, as the Adenocarpus hispanicus, Armoury caespitosa, Campanula herminii, carpetanus, Digitalis thapsi Crocus , carpetanum Doronicum, Festuca curvifolia, pentadactylis Linaria nivea, Saxifraga subsp. Vicentei willkommiana, Sempervivum, etc.
Throughout the whole National Park its Peripheral Protection Zone floristic catalog, approximately 446 taxa would form the flora of interest, belong to any of the following categories: endemic species, species in the area limit, rare and endangered species. Among these, about half would correspond to endemic species and the rest to finicola species. Only one fourth of these species of interest are protected in the flora legal protection catalogs (Spanish Catalog of Threatened Species, Madrid Regional Catalog of Endangered Species, Castilla y León Protected Flora).
List of protected species
|Amelanchier ovalis||Snowy mespilus||CREAM (vulnerable)|
|Androsace vitaliana subsp. assoana||LR (vulnerable)|
|Betula pendula||Birch||CREAM (special interest)|
|Betula pubescens subsp. celtiberica||Birch||CREAM (special interest)|
|Carex furva||CREAM (sensitive to habitat alteration)|
|Carex umbrosa subsp. huetiana||CREAM (sensitive to habitat alteration)|
|Corydalis intermedia||FPCL (focus)|
|Corylus avellana||Hazel||CREAM (special interest)|
|Eleocharis quinqueflora||CREAM (special interest)|
|Epilobium angustifolium||CREAM (vulnerable)|
|Eriophorum latifolium||Broad-leaved cottongrass||CREAM (sensitive to habitat alteration)|
|Erodium paularense||Geranium from el Paular||
The EAEC (vulnerable), LR (endangered),
|Erysimum humile subsp. penyalarense||LR (endangered)|
|Fraxinus excelsior||Downy birch||CREAM (sensitive to habitat alteration)|
|Gentiana lutea||Yellow gentian||CREAM (special interest)|
|Geranium bohemicum||FPCL (focus)|
|Geum rivale||CREAM (vulnerable)|
|Ilex aquifolium||Holly||CREAM (sensitive to habitat alteration)|
|Isoetes velatum||CREAM (sensitive to habitat alteration)|
|Juncus alpinoarticulatus subsp. alpestris||CREAM (sensitive to habitat alteration)|
|Juncus bulbosus||CREAM (vulnerable)|
|Juniperus thurifera||Albar juniperr||CREAM (sensitive to habitat alteration)|
|Lilium martagon||Martagon Lily||CREAM (sensitive to habitat alteration)|
|Luzula caespitosa||CREAM (vulnerable)|
|Luzula sylvatica subsp. henriquesii||CREAM (vulnerable)|
|Lycopodiella inundata||LR (vulnerable), CREAM (in danger of extinction)|
|Malus sylvestris||Wild apple tree||CREAM (special interest)|
|Melittis melissophyllum||Barstard balm||CREAM (sensitive to habitat alteration)|
|Menyanthes trifoliata||Water clover||CREAM (vulnerable)|
|Narcissus pseudonarcissus subsp. confusus||Spanish daffodil||CREAM (in danger of extinction)|
|Neottia nidus-avis||CREAM (vulnerable)|
|Paris quadrifolia||Herb paris||CREAM (vulnerable)|
|Pedicularis schizocalyx||CREAM (vulnerable)|
|Phyteuma spicatum||CREAM (vulnerable)|
|Pinguicola grandiflora||Large-flowered butterwort||CREAM (vulnerable)|
|Polystichum lonchitis||CREAM (in danger of extinction)|
|Potamogeton polygonifolius||CREAM (vulnerable)|
|Prunus avium||Wild cherry||CREAM (special interest)|
|Prunus padus||Bird cherry||CREAM (vulnerable)|
|Pyrola minor||CREAM (vulnerable)|
|Quercus petraea||Oak||CREAM (special interest)|
|Ranunculus abnormis||CREAM (vulnerable)|
|Ranunculus valdesii||CREAM (vulnerable), FPCL (focus)|
|Rosa villosa||CREAM (special interest)|
|Sambucus nigra||Elderberry||CREAM (special interest)|
|Secale montanum||CREAM (vulnerable)|
|Senecio boissieri||CREAM (special interest)|
|Sorbus aria||Whitebeam||CREAM (special interest)|
|Sorbus aucuparia||Rowan||CREAM (special interest)|
|Sorbus latifolia||Broad-leaved whitebeam||CREAM (sensitive to habitat alteration)|
|Spiranthes aestivalis||FPCL (focus)|
|Stachys alpina||CREAM (vulnerable)|
|Taxus baccata||CREAM (sensitive to habitat alteration), FPCL (focus)|
|Ulmus glabra||Wych elm||CREAM (sensitive to habitat alteration)|
|Utricularia australis||CREAM (vulnerable)|
|Utricularia minor||LR (endangered), CREAM (sensitive to habitat alteration), FPCL (focus)|
|Vaccinium myrtillus||Blueberry||CREAM (special interest)|
|Veratrum album||False hellebore||CREAM (special interest)|
|Viburnum opulus||Guelder rose||CREAM (special interest)|
The EAEC, Spanish Catalog of Threatened Species.
CREAM, Madrid Regional Catalog of Endangered Species.
FPCL, Castilla y León Protected Flora.
LR, Red List of Spanish Vascular Flora.