444 BOTANICAL GEOGRAPHY. 



sometimes in the form of a surface containing salt-water lagunes, at others 

 as a line of hills, and which at Malaga alone is covered with a more exten- 

 sive alluvial plain, the cultivated plants are confined to the hot zone (0' 600'), 

 as the sugar-cane, the cotton-plant, and sweet potato, the Date-palm and 

 Ceratonia, as also the migrated Agaves and Opuntias, with several indigenous 

 plants, as Aloe perfoliata and Withania ; excepting the white poplar, 

 indigenous trees are absent from this littoral district. Boissier enumerates 

 altogether 19 trees as belonging to the hot region, part of which, however, like 

 the Agrumae, are of foreign origin. The following only can be regarded as in- 

 digenous: Ceratonia, which ascends 2000', Zizyphus, Punica, Celtis australis, 

 and Populus alba, with those which extend into the following region, where 

 they become more common viz. Ficus carica (0' 3000', on the southern 

 slope 4000'), Olea europtea (vid. supra), Quercus Ballota and lusitanica 

 (3000'), Q. Suber (4000'), Q. Ilex (4500'), and Pirns Pinaster (vid. supra), 

 The following are the most important formations of the hot regions : a. 

 Maquis (Montebaxo). Shrubs from 3' 6' in height cover the greater 

 part of the sloping soil, consisting of Chamtfrops, several Cisti, viz. C. 

 ladaniferus, albidus, and Clusii ; Pistacia lentiscus, Rhamnus lycioides, and 

 Phillyrea, numerous Genista, most commonly Genista umbellata and Retama 

 spheerocarpa, and some oaks, beneath which numerous annuals and Grasses 

 flower in the whiter and spring, and, more rarely, herbs which are developed 

 at a later period. Shrubs of Nerium denote the humid soil of the banks of 

 rivers, b. Campi. On bare wastes are found predominating Thymbra capi- 

 tata, Lavandula multifida, Teucrinm Polium, and numerous herbs, among 

 which Centrophyllum arborescens is pre-eminent. In other places, these are 

 replaced by the social Macrochloa tenacissima. In addition to these two 

 principal formations, there are the Halophytes of the littoral district, those 

 plants which are indigenous to the marshes of Malaga, and lastly, the plants 

 of the cultivated part of the country, with its hedges of Agaves and Opun- 

 tias. The following plants belong to the endemic forms of the hot region 

 of Granada : Caltha europcea (Celastrus Voy^], Genista umbellata and 

 gibraltarica, Sarothamnus beeticus and malacitanus, Ulex Ixsticus, Leobordea 

 lupinifolia, Ononis Gibraltarica and filicaulis, Maeoselinum, Lagascce and 

 fcetidum, Lonicera canescens, Withania frutescens, Triguera ambrosiaca, Lycium 

 intricatum, Lafuentea rotundifolia (according to Willkomm, but it is absent 

 according to Boissier), Digitalis laciniata, Sideritis lasiantha and arborescens, 

 Salsola Webbii, Passerina canescens and villosa, Osiris quadrifida, Euphorbia 

 and trinervia, Quercus Mesto, Salix pedicellata, and Ephedra 



The second region (region montagneuse), or the region of the Spanish 

 plateau, is peculiar to Spain, and cannot be compared with the mountain- 

 vegetation of other European countries. By way of introduction to Boissier's 

 description, I shall premise here a remark upon the climatal cause of this 



