The garrigue mostly composes the vegetation of the Cinca Medio County. Area punished by centuries of intense pressure and transformations, currently occupies very small and fragmented areas. In the northern part of the region (Fonz), most mountainous, garrigue is enriched by the presence of oak, real maple (Acer monspessulanum) and a floristic cortege thermophilic (viburnum tinus, sarsaparilla, phillyreaangustifolia, etc.). Boxwood, hazel and Scots pine also appears; juniper and the Corsican" chinebro " (Juniperusoxycedrus) proliferate in the stony soil, the first being more scarce than the second. Many garrigues have resulted in degraded Kermes oaks, Sardinian (Quercuscoccifera ) and Escambron (Rhamnuslycioides). Sometimes with steppe (Cistusalbidus) formed by repeated fires and overgrazing in rosemary with gorse (Genistascorpius), sage (Salvia lavandulifolia), thyme or dry grasslands of "zerbero" (Brachypodiumretusum) with numerous species such as Serratulapinnatifida, S. leucantha and Globulariaalypum. Pasture - scrublands are characterized by "chunqueta" (Aphyllanthesmonspeliensis) which only abound in Fonz.
The Aleppo pine which is highly resistant to droughts is present in the area and some may have local character, as is the case in Terreu where, mastic and other Mediterranean plants like bufalaga (Thymelaeatinctoria) grow.The Cinca groves are very rich in this part of the river course, with many willows, poplars, narrow-leaved ash, poplar, "zapatera" (Coriariamyrtifolia) and oddities like barberry ( Berberisvulgarise) or buckthorn (Frangulaalnus) . There are also formations of tall grass ( Saccharumravennae, Imperatacylindrica, Sparganiumerectum, reed, sedge, cattails, etc.) and plants from cascajeras like "besque grass" (Andryalaragusina). In the Sosa River tamarisk (Tamarixcanariensis) is abundant. In the "gesas" or chalky hills abound rosemary with asnallo (Ononistridentata), resulting from the destruction of the garrigue, are rich in gypsicolous plants, spread like the "badallera" (Gypsophila struthiumsubsp Hispanic.), and rarer ones like the Lepidiumsubulatum or Launaeapumila.
In the salty steppes from Selgua and Conchelexist interesting halophyte plants such as the Chenopodiaceae of genres like suaeda, salicornia and salsola, plus some Limonium. The "espartales" of Lygeumspartum occupy deeper soils, while the white wormwood shrub (Artemisia herba -Alba) or "sisallo" (Salsola vermiculite) abound in places trodden by cattle. Due to the structure and consistency of the crags of the county, they are not easily colonized by plants. Still, the rock tea (Jasoniasaxatilis) is common. In the conglomerates ("Mallacán" of Monzón) or limestone in Fonz, flora is richer with ferns (Polypodiumcambricum, acrostic Cheilanthes, Aspleniumfontanum) pyrenea violet (Ramondamyconi) or Silenesaxifraga.
The flora of the Cinca Medio in data
In the area, we found a total of 1,035 vascular plants cataloged to date (about 30 % of the Aragonese flora). The Cinca Medio is a crossroads where different floristic elements converge.
* The Mediterranean floristic background is very important, with almost 45 % of all species, due to the prevailing climate in most of our region.
* The Euro-Siberian element, with own plants from Central Europe and common in mountainous regions, exceeds 16% of the regional flora which characterizes the cooler environments with an assured moisture.
* The sub-cosmopolitan plants globally widespread and much to the multiregional areas exceeds 30%, they consider the abundance of altered environments and the importance of agriculture, with its procession of associated ruderal and weed plants.
* Endemic, of more or less confined area, accounts for about 7% of the total and tend to focus on particular unique enclaves.
Biogeographic boundaries and rare plants
There are more or less frequent taxa in the Ebro Basin that have not been found anywhere else, but at the North of Cinca Medio. These include, among others, Aizoonhispanicum, Dianthus broteri, Inulacrithmoides, granatense Alyssum, Carexhispida and Salicorniapatula.
In contrast, other plants of montane character (sub-Mediterranean and Euro-Siberian) do not penetrate further south in this sector of our province, such as Helleborusfoetidus, Frangulaalnus, Clematis recta, Corylusavellana, Carexmairii, Origanumvulgare or Juniperuscommunis.
The unique and scarce native species of the region tend to concentrate in particular points. For example, in Fonz the Aster willkommii, spuria Iris, JuncusSphaerocarpus, Anthericumliliago or Fritillarialusitanica stand out. In Almunia de San Juan the Crocus nevadensis, Astragalusexscapus, or Euphorbia minuta and Nepetatuberosa. In Monzón, Cheilanthes acrostic, Berberis vulgaris or Atractyliscancellata .In Pueyo de Santa Cruz, Bassiahyssopifolia or Chenopodiumglaucum.In Alfántega, Iris lutescens.In Binaced, Allium moschatum or Centaurealinifolia.In Albalate de Cinca, Crucianellapatula and Narcissusdubius. In Alcolea de Cinca, PotamogetonnodosusorAstragalusturolensis. In Pomar de Cinca ( Terreu ) Biscutella Mediterranean, Cheirolophusintybaceus or Chronanthusbiflorus.
We have families and plant groups with few representatives (only 12 species of orchids and 11 ferns, for example), whereas the composed, Grasses and Leguminosea alone added 34% of the regional flora.
An emblematic case: The Cinca groves in Ariestolas
The remarkable width and the little slope of the middle course of the Cinca have resulted, in many aspects, with the proliferation of lateral mainstream channels. The remarkable development of different riparian plant communities, concatenated with other drier alluvial soils. The least violence caused by the floods while building the Cinca reservoirs has resulted in the setting of gravel and sand, thus the subsequent colonization by more permanent vegetation. In the groves of Ariestolas and Castejóndel Puente exist a wealth of communities and species along the bank of the Cinca's middle course.