GEOGRAPHICAL BOTANY. 341 



a. Fresh-water Formation. Amongst numerous Gra- 

 minaceae, Cyperaceae and Naiadeae, with Nymphaeaceae 

 and Typheae, it possesses but few forms which are charac- 

 teristic of the climate ; as, e. g. Vallisneria spiralis and 

 Marsileapubescens, Ten. (M. Fabri, Dun.) 



b. Formation of those soils which are occasionally 

 overflowed, are characterised, e. g. by Mentha cervina. 

 These are the localities of Cicendia Candollei and Conyza 

 sicula. 



B. Plants of the uncultivated part of the district. The 

 author believes that three or four formations may be dis- 

 tinguished, of which the first, that of the Cistaceae, is 

 more distinct than the rest are from each other. 



a. Garrigues, i. e. Formation of the Cisti. A stony 

 soil is densely covered with shrubs of Cistus or some 

 other firmly interlaced and frequently thorny bush. These 

 shrubby forms are the following : Cistus crispus, salvi- 

 folius, albidus, and monspeliensis ; Ulex provincialis and 

 Europaus ; Daphne Gnidium ; Quercus coccifera ; Erica 

 scoparia and cinerea, Calluna vulgaris ; PUillyrea angus- 

 tifolia and latifolia ; Lavandula Stcechas ; Osiris alba ; 

 Junipcrus Oxycedrus and communis, and Rosmarinus offi- 

 cinalis. Among other plants, the following are charac- 

 teristic : a number of species of Helianthemum, growing 

 with the Cisti, some Euphorbias, Santolina, Helichrysum 

 Stcechas, Aphyllanthes, &c. From this formation also 

 more than 40 species are enumerated. 



d. Duchartre has not been able to distinguish the pecu- 

 liarities of those surfaces and hills (campi) which are 

 covered with shrubs and annuals, and to illustrate them 

 according to their characteristic vegetable forms. We 

 shall, therefore, pass over this part of his memoir, and 

 merely mention some of the more rare species which 

 belong here : Biscutella coronopifolia, Linum salsoloides, 

 Centaurea Pouzini, and Echimn Pyrenaicum. 



c. Plants of the cultivated soil. 



a. Formation of the ruderal plants. The species are 

 all widely diffused. 



