( 125 ) 



Everywhere it is characteristic of physiologically dry plateaus and 

 rarely descends to the low-lying plains, as in the present case. 

 Drosera and the Cyperaceae also tend to emphasize the resemblance 

 to heaths. 



Through the other vegetation, of' which the sclerophyllous and 

 sclerocarpous Myrtaceae form an important constituent, this formation, 

 however, approximates much more to that which was called by 

 Schimper (Pflanzengeogr. p. 538) "Hartlaub formation" and of' which 

 he describes a number of' regions, occurring round the Mediterranean, 

 in California, in Chili, in South-Africa and in South-Australia. These 

 regions are all characterized by dry and hot summers, alternating 

 with moist winters. Hence climatologically there is little resemblance 

 between these and the padang-formation of Banka and Biliton, where 

 it rains almost the whole year. As regards the condition of the soil, 

 there is, on the other hand, a resemblance with the South-Australian 

 "scrub lands", described by Schomburgk in his Flora of South-Australia 

 1875. (See Schimper 1. c. p. 559). 



The dominant influence of the soil on the character of the forma- 

 tion cannot here be doubted; this influence, which according to 

 Schimper is relatively rare in the Tropics, has been but little in- 

 vestigated. (See Schimper 1. c. p. 405. Edaphische Wirkungen in den 

 Tropen). 



The padang-formation does not correspond even roughly with any 

 of the vegetation-pictures and formations, mentioned in that chapter. 

 As has been mentioned, it can only, to some extent, be compared 

 with tropical alpine floras and with the "■ Hartlaub formation" . 



The plants, collected by Mr. Ham, probably do not represent a 

 complete, but nevertheless give a very typical picture of this rather 

 poor flora. As regards the distribution of these plants, it is at once 

 noticeable, that not a single one of these occurs in Java, with the 

 exception of two wide-spread grasses, which have crept in from the 

 beach, namely Thuarea sarmentosa and Isachne auslralis, and with 

 the exception of the two pantropic ferns and of Psychotria viridi- 

 llora, which plants were, moreover, not found in the typical sand 

 padang. A wide distribution from Malacca to Australia through the 

 northern part of the Archipelago, but excluding Java (probably up 

 to and including Timor), is observed in the case of Baeckeafrutescens, 

 and also of Leptospermumflavescens, Rhodomyrtus tomentosa, Mchtleuca 

 minor, Th'osera Burmanni, Salomonia oblongifolia and Bromheadia 

 palustris. From Malacca and Borneo are known : Calophyllum 

 pulcherrimum, Garcinia bancana, Vaccinium mcdaccense, Leucopogon 

 malayanus , Arch>jt<icn \ r <ihlii , Wormia suffruticosa. From Banka 



