xiii.] FLORA OF THE KAPUAS LAKES 



In crossing the lake to visit Lampei I had not collected any 

 plants, for I was anxious to deposit my luggage and store of botanical 

 paper under cover in a dry place without delay. Next day, how- 

 ever, I devoted to an investigation of the flora of the lake, although 

 the season was, unfortunately, not too favourable, for many species 

 were not in blossom, and, as I have remarked already, the shrubs 

 and underwood were so entirely covered by water that we passed 

 over them in my boat. I was able, however, to collect about 

 thirty-five species of plants which I had not met with before in 

 Borneo. But altogether the flora of these lakes is not very remark- 

 able, and presented no conspicuous form which attracted my 

 special attention ; nor is it rich, consisting of some fifty odd species 

 only, generally abundant, though I should state that I have not 

 made an accurate examination of the species collected in that 

 locality. Except a few epiphytes, the others are shrubs or small 

 trees which appear to be specially adapted to live in freshwater 

 swamps. In this connexion two Brackenridgeas and a Dichilanthe 

 deserve to be noticed, being remarkable for the floating apparatus 

 with which their fruits are provided, 1 and also for the geographical 

 distribution of the species belonging to both genera. The Dichi- 

 lanthe of Danau Lamadjan (D. Borneensis, Baill.) is a singular 

 Rubiacea, .with blue irregular flowers similar to those of a Scrophu- 

 lariacea, in which the small calyx swells and becomes ventricose 

 on the maturity of the seeds, thus originating the floating apparatus. 

 Dichilanthe Borneensis is very similar to D. Zevlanica, Thw. — 

 the type species of the genus, and the only other one known — 

 which is found in the mountains of Ceylon. The Brackenridgeas 

 are Ochnacece, of which, besides the two found by me in the Kapuas 

 lakes (B. serrulata and B. pahtstris, Bartelletti), five other species 

 are known. One of these inhabits the Malay Peninsula, one is 

 found in Queensland, another in the Fiji islands, another in the 

 Philippines, and the remaining one at Zanzibar. The seeds of 

 a Brackenridgea have also been found floating on the sea. off the 

 coast of New Guinea. 2 On the whole, although the flora of the 

 Kapuas lakes is not remarkable for variety and beauty, I consider 

 that it is of special interest on account of sorrie of the peculiar 

 forms of adaptation which it possesses, owing to which the species 



1 The fruits of Brackenridgea are oval or rounded, only a few millimetres 

 in diameter, of a shiny black, and coated with a thin pulp. They must 

 therefore offer a certain attraction to birds, which probably contribute 

 to their diffusion. But these seeds also possess internal closed cavities 

 containing air, which enable them to float on water. This would explain 

 the wide geographical distribution of this genus. It is, however, not a 

 little strange that, notwithstanding the facilities for dispersion of the seeds, 

 the species are all much localized. 



2 Cf. Report of the Scientific Results of the Voyage of H.M.S. Challenger. 

 Botany, i. i. lxiv. E. 



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