Wind 65 



Phajus sp.). He includes the Cyperaceae (Cyperus digitata, 

 Fimbristylis spathacea, Lipocarpha foliosa) and the two Grasses, 

 Spinifex squarrosus and IscJiaemum muticum in the group of 

 " roophilous species," that is, species distributed by water. In April 

 1906 the floras of the three islands included twelve Composites 

 {Conyza august ifolia, Conyza indica, Erechthites hieracifolia, 

 Wedelia glabrata, Senecio sp. 1 introduced since 1897); six Gramineae 

 (excluding Isclmemum and Spinifeoc; Peunisetum elegcms added since 

 1897) ; four Cyperaceae (Mariscus umbellatus, a new arrival since 1897) 

 and five Orchids (Cymbidium Finlaysonianum since 1897). In the 

 case of all these 28 species (30 % of the phanerogam flora) wind-agency 

 has probably been the means of transport; in some instances other 

 means of dispersal are also possible and were perhaps concerned in 

 the colonisation of Krakatau. Of these 28 presumably wind-borne 

 species, some are found also in the strand vegetation of Krakatau and 

 occur on the coasts of Java and Sumatra as often as in the interior. 

 The possibility of transport of the fruits by water is by no means 

 excluded, at least as regards such members of the flora as Conyza 

 indica, the species of Blumea, Wedelia and Wollastonia which are 

 especially common on the beach and are reckoned by Schimper among 

 the typical strand-plants. In the flora of the island of Edam, and at 

 localities on the coasts of Java and Sumatra which we visited, Compo- 

 sites were not uncommon ; on Edam we found six (two of which occur 

 also on Krakatau, Vernonia cinerea and Wedelia glabrata) ; at Vlakke 

 Hoek, the ubiquitous strand-plant Wedelia glabrata ; at Java's First 

 Point four (three of which, Blumea bcdsamifera, Wedelia glabrata 

 and Vernonia cinerea occur also on Krakatau). Some of the Grasses 

 included in the list occur not only in the coast-flora of Krakatau, but 

 are also common in that of Java, Sumatra and elsewhere: Imperata 

 arundinacea, for example, is mentioned by Hemsley as a strand-plant 

 which owes its distribution to sea-currents. On the other hand he 

 expresses doubt as to the efficacy of this means of dispersal in the case 

 of Composites, while Schimper lays stress on the fact that the small 

 fruits of most of the strand Composites and those of the species 

 Wedelia biflora, with the widest oceanic distribution, are not provided 

 with a pappus and are therefore ill-adapted for dispersal by wind. 

 We cannot go far wrong if, without accepting his argument against 

 wind-dispersal as convincing, we follow Schimper in admitting that 

 some of the Composites of the strand -flora may have been carried 

 by sea-currents. 



1 Senecio sp., presumably also Conyza indica, Conyza angustifolia, the species 

 which were found by Treub in 1886. (Treub, loc. cit. p. 218, "deux especes de 

 Conyza.") 



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