Pyrenean flora is rich and the different levels of vegetation are very visible in the landscape.

Indeed the higher the altitude the more difficult the living conditions for plants :
Summer is short, rain level is important, winds are violent, snow coverage lasts longer, yearly average temperatures are lower

(-1ºC per 200 m), light is intense, temperatures at ground level are high and the soils are poor in water. Thus each altitudinal level has its own specific kind of vegetation.

- From 900 to 1800 m : Montane level.
It is cool and humid and this is where the cattle remain. On the North slopes forests are made up of beech and fir trees. On the sunny South slopes forests are mainly made up of Scots pines. Characteristic flowers at this level : Radish-leaved Bittercress and Pyrenean Valerian.

- From 1800 to 2400 m : SubAlpine level.
Characteristic vegetation : Sparse Moutain pines forest, Alpenrose moors, Birches and Rowans... Flowers : Pyrenean Turk's Cap Lily and Pyrenean Iris, Carline-leaved Thistle, Pyrenean Fescue...

- From 2400 to 2900 m : Alpine level.
The only trees able to survive here are the dwarf willows.

They hug rock surfaces. The vegetation grows at ground level : Moss Campion, Pyrenean Poppy, Irati Saxifrage...

- Above 2900 m : Nival level.
Only Lichens and Algae can survive here.
How do plants adapt to life at altitude ?

Some plants live on several levels but they assume different shapes.

Junipers grow upwards in the valley bottoms and creep on the ground at the subalpine level, their leaves are also shorter and thicker.

Plants manage to resist climatic conditions through physical and physiological adaptation : reduction of the size of the stem, hairy leaves to keep in the moisture, hugging the ground to take advantage of warmer temperatures...

What is an endemic species ?
An endemic species is a species which has evolved in one place for

a very long period of time and has progressively changed to adapt to local ecological conditions.

Pyrenean endemic species have specific characteristics which are not found anywhere else.

There are about 160 "Pyreneo-Cantabrian endemic" species : Ramondia, Pyrenean Treacle Mustard, Fringed Rock-Jasmine, Pyrenean Rock-Rose, Silvery Vetch...
This high number is due to the isolation of the Pyrenees and the Cantabrian range in relation to the other European mountains.

GREY-WILSON (Christopher), BLAMEY (Marjorie) - Guide complet des fleurs de montagne -
Ed. Delachaux & Niestlé : Paris, 1990
DUPIAS (Georges) - Fleurs du Parc National des Pyrénées - Ed. Parc National des Pyrénées : Tarbes, 1987
SAULE (Marcel) - La grande flore illustrée des Pyrénées - Ed. Milan : Toulouse, 1991
MAYOUX (Philippe) - Fleurs des Pyrénées - Coll. Faciles à reconnaître - Ed. Rando éditions : Ibos, 1996
DANTON (Philippe), BAFFRAY (Michel) - Inventaire des plantes protégées en France -
Ed. Nathan : Paris, 1995
RAMEAU (J.C.) - Flore forestière française, t2 montagnes - Ed. IDF : Paris, 1993
FOURNIER (R.) - Les quatre flores de France - Ed. Lechevalier : Paris, 1990
RAYNAL-ROQUES (A.) - La botanique redécouverte - Ed. Belin, INRA Editions : Courtry, 1994