344 GEOGRAPHICAL BOTANY. 



Spanish plateau, between the Ebro and Xucar, traverse 

 the province from west to east as far as the sea. This 

 broad mountain -range, which is about 6000' in height, 

 and intersected with deep Barrancos, was once covered 

 with forests of Coniferse, the only remains of which at 

 the present time are isolated stems of Pinus Halepensis. 

 The dry slopes, which are almost entirely free from springs, 

 are now overgrown with a low bush (Montebaxo), the 

 extreme summits only being bare. Willkomm admits 

 the following stages in the Mediterranean vegetation of 

 this region, which attains an unusual elevation, ascending 

 to 4000'. 



500'. To about this height the Opuntias and 

 Agaves extend, together with the culture of Ceratonia. 

 The Montebaxo consists of Chamber ops, Erica arborea, 

 Daphne Gnidium, Retama sph(erocarpa, Ulex, Rosmarinus, 

 and some oaks. 



500' 2000', i. e. as far as the upper limits of Cha- 

 mcerops (also of Retama, Juniperus Oxycedrus, and Pis- 

 tacia Lentiscus). Rosmarinus and Chamarops predomi- 

 nate; in addition to those already mentioned, Erica 

 arborea from among those of the first stage, and Rhamnus 

 lycioides, Pistachio, Terebinthus, and some Cisti are here 

 first met with. Characteristic Grasses : Macrochloa te- 

 nacissima and Stipa juncea. 



2000' 4000' up to the limits of the cultivation of the 

 olive and wheat. The greater part, however, of the slopes 

 at this level consists of uncultivated mountain-land. In 

 a Montebaxo, the principal plants associated here with 

 Rhamnus, Rosmarinus, Erica, and Cisti, are Juniperus 

 Phcenicea, Fraxinus sp., Arbutus unedo, and Quercus Ilex. 



Isolated pine-trees and a Montebaxo formed of Vlex 

 Australis and Juniperus Phcenicea characterise the re- 

 gion extending from 4000' 5500', which may be dis- 

 tinguished from the Mediterranean by the occurrence of 

 the plants of the north of Europe. On the summit of the 

 Monte de la S. Maria (5500' 6000'), of woody plants, 

 Arctostaphylos uva ursi, Taxus, and some Cotoneasters 



