APPENDIX 



stages of growth are small and very different from those which are 

 formed later. They are also flattened against the bark of the tree to 

 which the plant adheres. But when the creeper has gained strength 

 its upper leaves change their form, detach themselves from the supporting 

 trunk, and may even acquire considerable dimensions, as in the case of 

 some Aracece of the genera Raphidophora, Epipremnum, Scindapsus, 

 etc. 



Stenophyllous Plants. — I have adopted this term for certain plants 

 growing on river banks, or in the beds of torrents, which have linear 

 or else very narrow leaves — narrower than those of congeneric species 

 growing in the forest. By this I do not mean that every plant with narrow 

 leaves must of necessity grow by the side of rivers, nor that it is only 

 on Bornean rivers that such are observable. That plants with linear 

 leaves have such a habitat is well known, and I need only mention as an 

 example the many species of Salix so frequent in such localities. In 

 Borneo however, along the inland rivers, stenophyllism appears to me 

 much more accentuated, and more instructive by reason of the fact 

 that the plants exhibiting this characteristic are numerous, and in 

 many cases very strictly localised. They thus give one the idea of growing 

 on the spot where they were originally plasmated ; where, submitting 

 to local influences, they modified their structure, and more especially 

 their leaves, in compliance with the stimulus received. I am inclined 

 to ascribe the stenophyllism as due to the action of the continuous 

 currents of air, so constant along rivers, and, secondly, to that of periodical 

 floods. In the latter case stenophyllism is associated with great flexibility 

 and toughness of the stems and branches, such as that exhibited by 

 several species of Salix. To this type I refer Croton viminalis, Becc. 

 (P. B., No. 3824) ; Nauclea rivularis, Becc. (P. B., No. 3827), which is 

 allied to N. angusti folia, Haviland ; Tetranthera salicifolia, Becc. (P. B., 

 No. 3826) ; and two Antidesma (P. B., No. 3829, 3831), besides some sub- 

 herbaceous plants, such as Osmoxylon helleborinum, Becc, and Pinanga 

 rivularis, Becc, and perhaps an orchid (Arundina, P. B., No. 3839). 



To the group of stenophyllous Bornean plants resulting from the action 

 of fluviatile air-currents one may, I think, refer Garcinia linearis, 

 Pierre, from the rapids of the Rejang and the banks of the Entabei ; 

 F agrcea stenophylla, Becc. (P. B., No. 3863), and Erycibe longifolia, Becc. 

 (P. B., No. 3832) of the same region, where I also found, belonging to the 

 same type, Syzygium Nerifolium, Becc. (P. B., No. 3862), Eugenia 

 riparia, Becc (P. B., No. 3880), Psycotria acuminata, Becc. (P. B., No. 

 3840), Saurauja angustifolid, Becc. (P. B., No. 3774), a Milletia (P. B., 

 No. 3828), and Pinanga calamifrons, Becc. 



It is certain that in my necessarily rapid exploration of the Rejang 

 and other rivers of that region, I cannot have collected all the plants of 

 a stenophyllous type which grow there, and I have no doubt many 

 additions will be subsequently made to the species I have enumerated. 

 I believe also that, although these species appear to be highly localised 

 forms, they may be found along other rapid rivers subject to sudden 

 inundations in the central parts of Borneo. But it is certain that plants 

 of this type are not frequent on the west side of Borneo visited by me, 

 and I can only recall a Fiats (F. riparia, Becc, P. B., No. 2781), from 



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