BOTANICAL GEOGRAPHY. 433 



Ann. Rep. for 1843), we cannot enumerate these mountains among the 

 independent centres of vegetation of the flora of Germany, because the 

 whole of their Phanerogamia may be regarded as having migrated from the 

 Alps, the Vosges, the Jura, or the Rhenish mountains. 



3. The rugged Alp (Swabian Jura) possesses the characteristic vegetation 

 of the Jura-limestone, which is uniformly distributed from Switzerland to 

 Franconia. However, although the mean level of the elevated surface 

 amounts to more than 2000', and individual summits ascend to more than 

 3000', the alpine forms of plants, which are common on the higher Jura of 

 Switzerland, are for the most part absent here, and even the few species 

 (7 sp.) which belong to this category, are in most cases found at single spots 

 only ; whilst on the other hand, many calcareous plants from the valleys of 

 the Bavarian Alps are common here. About 50 species are found in "Wur- 

 teniberg on the rugged Alp only, 34 calcareous plants occur in common with 

 the region of the Neckar, 1 8 species with Upper Swabia only, 16 others 

 with both these districts, and 5 with the Black Forest. Perhaps the follow- 

 ing from the list of plants peculiar to the Swabian Jura might be mentioned 

 as characteristic forms, omitting those which are diffused over the calcareous 

 Alps : Thalictrum galioides, Thlaspi montanum, Sisymbrium austriacum, Ery- 

 simum crepidifolium and odorattim, Dianthus ctesius, Linum flavum (at Ulm), 

 Coronilla montana and vaginalis, Sorbus latifolia, Leontodon incanum, Doroni- 

 cum Pardalianches, Jasione perennis, Specularia hybrida, Digitalis lutea, 

 Nepeta nuda, Orchis pallens, Aceras anthropophora, and Iris Germanica. 



4. The tertiary plain of Upper Swabia lying between the Jura and the 

 Alps, 1250' to 2000' above the level of the sea, is geographically a portion of 

 the plateau of Upper Bavaria, and also contains its vegetation, whilst the 

 Jura agrees with it far less than might have been expected. Even the peat- 

 moor formation is the same here as in the bogs of Bavaria. Upper Swabia, 

 although it has been least explored botanically, probably contains more plants 

 than any other part of Wurtemberg, on account of its fertile calcareous 

 Molasse-soil, the considerable variations of its elevation, the abundance of 

 water, and the proximity of the Alps from which, as in Bavaria, many plants 

 are washed down. The list of those plants of Upper Swabia which have 

 not hitherto been observed in other parts of Wurtemberg, includes about 

 90 species. 



The following from among them, excluding the alpine plants, may be men- 

 tioned as characteristic : Ceratocephalusfalcatus, Viola lactea, Linum viscosum, 

 Alsine stricta, Potentilla norvegica, Saxifraga Hirculus, Helosciadium repens, 

 Gentiana wtricularis, Pedicularis sceptrum, Primula acaulis, Betula humilis, 

 Stratiotes, Iris graminea, Allium suaveolens, Juncus tennis, Carex capitata, 

 microglochin, chordorrhiza, cyperoides, and Heleonastes. 



Mohl makes some ingenious observations on the distribution of alpine 

 plants towards the Bavarian plateau of Upper Swabia. He distinguishes 



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