247 



they were collected at Zwarte Hoek or on the eastern side of the 

 island. Of not a single species the frequency is mentioned. Hence it 

 is impossible to draw from this most unsatisfactory list conclusions 

 as to possible modifications of the littoral flora since the time of 

 former excursions, nor will anyone be able to do so in future years. 

 It can only be stated that in 1919 not a single littoral plant (with 

 the exception perhaps of Mucuna gigantea D. C., for which see 

 beneath) was found on Krakatao that had not already been collected 

 in 1908 or former years. No less than six or seven littoral species or 

 mangrove-components found at previous excursions (Albizzia retusa 

 Bth.,- Dodonaea viscosa /acq. ') - In igofera zollingeriana Miq.,- 

 Sophora tomentosa L., Thespesia populnea So/and.,- Ximema ame- 

 ricana L. and Xy/ocarpus granatum Koen.) were in 1919 not found 

 back or at least not collected on the main island. This, of course, 

 is by no means proof that they were not present then, as even large 

 plants may be easily overlooked by unsufficiently trained and careless 

 collectors. Of seven other littoral plants or halophytes which according 

 to Appendix I of the Dutch and English texts were collected on 

 Krakatao during the short trip made in October 1919 by the members 

 of the Congress to that island, but not in April of that year, no less 

 than 5 (Cerbera manghas L. - Hernandia peltata Meissn.,- Mucuna 

 gigantea D C. ^), Pongamid pinnata Merr. and Vitrx paniculate 

 Lamk. :i ) are not recorded in Appendix II, though it can hardly be 

 believed that they were not growing on or quite near the beach. 

 Perhaps Mr. Docters van Leeuwen, though recording them in 

 Appendix I as having been found on Krakatao, excluded them from 

 Appendix II because he did not know them to be beach-plants. But 

 this cannot be considered a valid reason, because information on 

 this point was easily available. The two other species (Acrostichum 

 aureum L. and Morinda citrifolia L.) are recorded in Appendix 11 

 (No. 77 and 45). 



!) In a subsequent paper [Dr. W. Docters van Leeuwen, The Vegetation of 

 the Island of Sebesy, situated in the Sunda-strait, near the Islands of the Krakatau- 

 group; in the year 1921 in Ann. ]ard. Bot. Buitenzorg XXXII (1923), p. 146 J it is affirmed 

 however that this species occurred (when?) in the forest of Casuarina equisetifo/ia. 



-) In the Dutch text the name is given as Mucuna prune/is D- C, which is 

 an inland plant, found but rarely on the beach and only on its older parts- It was 

 collected in 1906 on Verlaten Eiland and recorded by Ernst. In the English text of 

 Mr. Docters van Leeuwen's paper the name of the specimen found in 1919 has, 

 without any comment, been changed into M. gigantea D. C-, which is a plant of the 

 beach and the localities immediately behind it. In this same text the specimen found 

 in 1906 on Verlaten Eiland is also and wrongly - reduced to M. gigantea D.C.It is a 

 difficult task to unravel the mess made by Mr. Docters van Leeuwen. 



3 ) See p. 183, No. 41. 



