Chap. II] 



REGIONS OF VEGETATION 



711 



that the production of flowers is favoured, for they developed at a rela- 

 tively earlier stage: 'whilst in Viola arvensis, in the experimental bed at 

 Vienna, the buds in the axils of the foliage-leaves 1-6 were suppressed and 

 flowers first appeared in the axils of the 7th and 8th foliage-leaves, in the 

 alpine experimental garden flowers were developed even from the axillary 

 buds of the 3rd and 4th foliage -leaves.' 



In many plants of his mountain cultures, Kerner 2 observed a bleaching of 

 the vegetative organs, owing to the partial decomposition of the chlorophyll, 

 for instance in Arabis procurrens, Digitalis ochroleuca, Geum urbanum, and 

 Orobus vernus. Linum usitatissimum even perished, apparently owing to 

 the complete destruction of its chlorophyll. In other species the green 

 colour of the foliaged shoots was concealed by rich formation of anthocyan. 

 Thus Satureia hortensis, which has only 

 a slightly reddish tint in the lowlands, 

 became deep reddish-brown in the alpine 

 garden, as did also the species of Se- 

 dum that are pure green in the lowlands, 

 Dracocephalum Ruyschiana, Leucanthe- 

 mum vulgare, Lychnis Viscaria, Bergenia 

 crassifolia, Potentilla tiroliensis, and the 

 tips of grasses. 



Bonnier and Kerner agree that the 

 jlowers in their mountain cultures usually 

 possessed a more intense colour than in the 

 parallel lozvland cultures. There is not 

 always a difference, and where one exists 

 it is not always very marked. Most 

 striking was the favourable influence of 

 the mountain climate on the formation of 

 pigments in the case of flowers that are 



white in the lowlands, but acquired a more or less deep carmine-red colour 

 in alpine cultures ; such, for instance, as Libanotis montana and Trifolium 

 repens. Among flowers that are also coloured in the lowlands, but, according 

 to Kerner, become darker in the mountain climate, Agrostemma Githago, 

 Campanula pusilla, Dianthus sylvestris, Gypsophila repens, Lotus corni- 

 culatus, Saponaria ocymoides, Satureia hortensis, Leontodon Taraxacum, 

 Vicia Cracca, and V. sepium are striking examples. Bonnier has illus- 

 trated the differences in a number of flowers by means of a table of colours. 

 According to this the darkening of yellow flowers appears to consist in 

 the manufacture of red or violet colouring matter, probably dissolved 

 anthocyan, as in the red and blue flowers that normally contain it. The 

 yellow carotin appears to be unaffected. 



1 Kerner, II, p. 392. 



Fig. 413. Alpine flora of the Andes. Peren- 

 nial rosette-plants. i. Viola granulosa, 

 Wedd. 2. Viola pygmaea, Juss. et Poir. 

 Two-thirds natural size. After Weddell. 



