55 



the interior, up to an altitude of 700 m, locally often in great num- 

 bers. In the surroundings of Batavia and Tandjong Priok it is rather 

 common, especially along pools and ditches with sweet or slightly 

 brackish water. Usually it climbs with the aid of its rhizomes 

 high against the trees; where these are absent it can form as 

 was already mentioned thirty years ago by the excellent observer 

 Raciborski *) dense groups with creeping rhizomes. The re- 

 production is effected as well by these rhizomes as by spores which 

 are easily spread by water. In May 1908 I found this plant in ravine- 

 mouths on Lang Eiland, on which island it had been found already 

 in 1896 by B o e r I a g e, also in ravines. Probably the rather feeble, 

 sterile specimen of Treub was gathered in a such-like habitat. 

 According to Raciborski 1 ) the plant was in 1 897 numerous on 

 the north-western side of Krakatao. 



3. Blechnum orientale L 



Terrestrial fern, in Java one of the most common kremnophytes -) 

 from the plains up to an altitude of 1600 m., except in regions where 

 the east-monsoon is very strong. As a rule it grows on perpendicular 

 banks and steep roadsides where it often locally predominates. The 

 reproduction is effected exclusively by spores. In 1886 the north- 

 western part of Krakatao offered it many localities fit to grow in 

 and it is quite possible that it occurred then in many specimens. 



4. Acrostichum aureum L. :i ). 



Hygro-halophyte, chiefly growing in coastal marshes and also in 

 salt or brackish, swampy localities in the interior ''), up to many 

 hundreds of metres above sea-level, rather rarely in sweet water and 

 then only in scattered specimens. Along the clayey coasts of Java 

 this very coarse fern is quite common in many localities, frequently 

 rather far from the sea; the surface of the water is often coloured 

 brown by myriads of floating spores, the only means of reproduction. 

 In 1886 it may have grown in the north-western part of Krakatao 

 in the mouths of the lower ravines with a saline soil (Cf. p. 50, 

 footnote 3). 



*) Die Pteridophyten der Flora von Buitenzorg (1898), p. 55, under the name of 

 Acrostichum scandens /. 5m. 



2) Cf. p. 31. 



') By some mistake Treub wrote Acrostichum aureum Cav. Tliis fern, at present 

 named Ceterach aureum L- v. Buch, is an inhabitant of the Canaries. The specimen 

 collected by Treub was Acrostichum aureum L. 



4 ) For such localities mentioned already almost a century aqo by B I u m e [Flora 

 javae, Filices, p- 40 (under the name of Acrostichum inaequale Wi/ld)]. 



