upon the Distribution of Vegetables. 177 



excluded ; and hence, in particular, the existence of marine, 

 fluviatile, and lacustrine plants ; hence also the analogy sub- 

 sisting between the vegetation of salt marshes and that of the 

 sea shore. 



It cannot be denied that calcareous strata possess a Flora 

 very different from that of all others. Zuccarini and Sieber 

 observed this fact, upon the south side of the Alps; in the Car- 

 pathian mountains, Wahlenberg counted forty-three plants 

 which belong only to a calcareous soil ; and he made the 

 same observation in Sweden. On the new continent, Martius 

 was struck with the same facts, in the neighbourhood of the 

 river San Francisco, where the chalk begins ; he there per- 

 ceived vegetation to assume a peculiar character, remarkable 

 for the predominance of certain forms, as those of the Tere- 

 binthaceai, Malvaceae, Solanece, Ficoidece, mimosas, and cas- 

 sias. There are plants peculiar to gypsum, as many of the 

 Gypsophilce, the Gymnostomum curvirostrum, Urceolaria 

 gypsacea, Sarcosyphus gypsophilus, Wall. The vegetation be- 

 longing to quartz, chalk, and clay, is never entirely different, 

 because these substances do not occur pure, but are always 

 accompanied by others, and covered with soil which is eve- 

 rywhere the same. The plants peculiar to quartz, for exam- 

 ple, are Arundo arenaria, Plantago arenaria, Jasione mon- 

 tana, Statice Armeria, Gnaphalium arenarium, &c. In the 

 argillaceous strata we find, on the contrary, Tussilago Farfa- 

 ra, T. Petasites, Arctium Lappa, Sonchus arvensis, Inula 

 dysenterica, Thlaspi campestre, &c. But these influences 

 operate only when the formation occupies a very large surface; 

 it is thus that I found upon the lignite in the vicinity of Hae- 

 ring, in the Tyrol, only Funaria hygrometrica, as peculiar to 

 it ; the other plants were the same as in the environs, and had 

 invaded the little plot of lignite. The turfy strata likewise 

 have a vegetation peculiar to themselves, and their influence 

 is such that we may recognise the same species upon the turf 

 beds of different parts of Europe ; as if the influence of the 

 soil preponderated over that of the climate itself. The vege- 

 tation of the province of Minas-Geraes, according to Martius, 

 is the most distinctly characterised of that of the Campos, and 

 is never observed upon calcareous or granitic strata. 



Nevertheless, observations have been made which appear 

 to invalidate the correctness of the preceding. Wahlenberg 

 observed on the Carpathian mountains, thirty -nine plants con- 

 sidered to belong exclusively to the calcareous formations ; 

 of these thirty -nine plants he afterwards met with twenty-two 

 on the granite in Switzerland and Lapland. Schouw, travers- 

 ing the whole of Switzerland and the Apennines, with a ge- 



