300 PSILOPHYTES sect, xiii 



belong to this formation, and Kurz,i has described several forms of 

 savannah-forest occurring in Burma. 



Eucalyptus-forest. 



Allied to tropical savannah-forest is the Eucalyptus-forest in sub- 

 tropical parts of eastern Australia where the rain falls in summer. In 

 this open, well-lighted, evergreen forest the trees stand so far apart that 

 their crowns do not meet. The ground is clothed with a continuous 

 carpet of grass, including an admixture of perennial herbs, which sprout 

 forth at the beginning of the rainy season and form a fresh, lush sward. 

 In the dry season many of the plants vanish, the longest to remain being 

 the grasses and Compositae, as in Brazilian campo. The country, viewed 

 from a distance, appears to be densely clad with forest ; yet one can ride 

 through the forest, and travel freely in all directions. There is a close 

 likeness to Brazilian campos serrados, but the trees are taller and more 

 slender, while the number of species present seems to be small. 



Aphyllous forest. 



Apparently very closely allied to savannah-forest is the peculiar 

 tjemoro-forest, which is formed by species of Casuarina, and occurs on dry 

 bare soil on the mountains of eastern Java and the Sunda Isles. Atmo- 

 spheric precipitations are small in amount, and are not retained by the 

 porous soil : the vegetation consequently must be xerophytic. Casuarina 

 derives its protection against excessive transpiration from the charac- 

 teristic construction of its shoot : the shoots are Equisetum-like, almost 

 aphyllous, terete, and have a dark, matt, green surface, while their 

 stomata often lie within deep furrows on the twigs. Schimper^ has 

 supplied a description of a forest of this type occurring on the Javanese 

 mountain Ardjuno at an altitude of 2,500-3,000 metres. The ground is 

 covered with the brown, dead, acicular twigs of Casuarina, just as it is 

 in a European pine-forest with pine-needles. On this covering grow 

 some herbs, including the narrow-leaved Festuca nubigena and Euphorbia 

 javanica, which occur in great numbers. Cushions of a small unscented 

 violet (Viola serpens), Plantago asiatica, small, white-flowered Umbelli- 

 ferae (species of Pimpinella), small species of Gnaphalium, and, above all, 

 Pteris aquilina, give a European cast to the flora. On less sloping spots 

 the vegetation becomes more vigorous, and several kinds of shrubs, 

 including species of Antennaria and Rubus pruinosus, are added to it. 

 Among the herbs, Sonchus javanicus recalls the European S. arvensis, i 

 while Valeriana javanica is very like the European V. officinalis ; in I 

 addition, other European genera are represented by Ranunculus prolifer, 

 Galium javanicum, Alchemilla villosa, Cynoglossum javanicum, Thalic-i 

 trum javanicum, and Agrimonia javanica. Mosses are very scanty. | 



Trees in relation to Savannah and Steppe. 



All savannahs, prairies, and possibly grass-steppes, suggest the!j 

 question : ' Why should trees be absent, or be few and scattered ? ' The i 



^ S. Kurz, 1875. ^ Schimper, 1893. j 



