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Botany. — " Lindeniopsis. A new subgenus of the Rnbiaceae" . By 

 Dr. Th. Valeton (Buitenzorg). 



During an official journey through the island of Billiton in March 

 1907 Mr. Ham, Inspector of Forests in the Dutch East, Indies, gathered 

 a small, but not unimportant herbarium collection, which he gave 

 over to me for study. 



The importance of this collection mainly depends on the fact, that 

 it was formed on lands, which are extremely rare in the Indian 

 Archipelago, and are as yet ilorally almost unknown. These are the 

 socalled "padang" lands (compare Verbeek in Jaarboek Mijnwezen 

 1897, p. 60 and 61). The soil of these lands consists of young, loose 

 sediments of recent origin, namely quartz sand and clay, both often 

 containing iron and manganese ; the soil, however, owes its peculiar 

 character to the presence of a mineral, which the Chinese call 

 fo sau kak and which consists of quartz sand, which has been moulded 

 together by organic acids into a pretty firm, dark brown sand-stone. 



"These padang lands are characterized by a sparse and peculiar 

 vegetation, in consequence of the small permeability to water of the 

 "/o sau kak", so that level padang-lands are frequently inundated 

 after heavy rains, and the roots of the plants, which can only pene- 

 trate with difficulty into the hard u fo sau kak", rot and die off." 

 (Verbeek I.e.). 



Besides in Billiton, these padang soils are also found in Banka 

 between Doeren and Boekit (Verbeek I.e.). In other parts of the 

 Archipelago they do not appear to be known. The most important 

 of these lands are found in the north and north-east of the island, 

 between Boeding and Manggar, and were studied botanically by 

 Mr. Ham. 



From verbal information and from the journal of the voyage, 

 which Mr. Ham kindly lent me for perusal, I obtained the following 

 data : 



The appearance of the padang soils is not everywhere the same. 

 Mr. Ham distinguishes : 1 grass padang, often rich in flint, where 

 grasses and sedge-grasses predominate, 2 fern padang where ferns 

 {Pteris aquilina L., Nephrolepis acuta Presl.), form almost the whole 

 vegetation, being only mixed with Xyris microcepliala Hassk., Fim- 

 bristylis spec, Melastoma spec, Ccdophyllum puleherrimum Wall., 

 Psychotria viridijlora Bl. and 3 sand padang, where the soil con- 

 sists of blinding white quartz sand. The white layer varies in thick- 

 ness from l /„ — 5 centimetres ; under this the soil is grey, obviously 

 through humus, and somelinies il is grey immediately below the 



