284 EREMOPHYTES SECT, xi 



bare is shown by Comics' interesting Plates, 1 on which are exhibited 

 the carefully plotted and measured areas occupied by individual 

 species. 



Among phenomena belonging to this steppe may be mentioned ' rolling- 

 plants \ 2 which are represented by Gypsophila paniculata and Rapistrum 

 perenne. When these are dead they are dislodged by wind, become 

 matted together into spherical, often gigantic masses, which the storm 

 drives bounding over the plains in great leaps (hence the popular name 

 ' steppe-witch '). 



The Russian steppes 3 are continued eastwards into the grass-steppes 

 of south-western Siberia. 



In Hungary. 



The Hungarian pusztas 4 are in general very similar to the steppes of 

 southern Russia ; the two agree in oecology, succession of events, growth- 

 forms present, and partly in species represented. Kerner distinguishes 

 divers associations, for instance : 



The feather-grass (Stipa) association. 



The golden-beard association, consisting of tall tufts of Andropogon 

 Gryllus which grow close together and thus produce vegetation, deviating 

 from that of typical steppe. 



In Roumania and Servia. 



The lowland of Roumania likewise shows a close affinity to Russian 

 steppe. 5 On sand} 7 soil in Servia there are steppes 6 whose vegetation 

 is composed of xerophytic grasses, perennial herbs, bulbous and tuberous 

 plants, shrubs, and annual herbs. The leaves are vertical or bent 

 upwards. Many leaves are capable of becoming furled, or protect them- 

 selves from insolation by photometric movements. Other plants defend 

 themselves by reduction of the leaf-surface. The roots are long. 



In Iberia. 



The dry character of Spain has brought into existence true steppes 

 in several places. These have been described by Willkomm, 7 who has 

 supplied the following statistics as to the share taken by different kinds 

 of plants in the composition of the vegetation : herbs, f ; undershrubs, 

 ; grasses, ^ ; shrubs, more than -^ ; lichens and algae, o 1 ?- Approxi- 

 mately one-sixth of the species have a vivid green colour, and the remainder 

 show other tints. 



Among interesting species in Iberian steppes we may mention the 

 halfa-grass (esparto-grass, Stipa tenacissima) and Lygeum Spartum, 

 which clothe wide areas of Spanish upland with their large stiff tufts and 

 so represent the Stipa-grasses of Russia. They give rise to special asso- 

 ciations on littoral steppe. Other Iberian steppe-grasses are Stipa 

 parviflora and Avena filifolia. 8 According to Rikli the littoral steppes in 

 the south-east of Spain belong to very xerophytic types, and are most 



1 Cornies, loc. cit. * See p. 277. 



3 In regard to Russian steppes, consult Kusnezow's abstract of Russian litera- 

 ture published in Engler's Bot.Jahrb., xxviii ; Tanfiljew, 1905. 



4 The name ' puszta ' signifies desert. 5 Grecescu, 1898. 

 Adamovicz, 1904. ' Willkomm, 1852, 1896. 

 " Rikli, 1907 b. In this paper figures of the leaf -anatomy are given. 



