Journal of the Royal Society of Western Australia, 86(1), March 2003 
alien species that does not occur in Western Australia 
(Hussey el al. 1997). The habitat still exists, but H. 
verticillata has disappeared, and it is likely that it was 
eradicated because of its resemblance to Elodea, an 
declared alien species. One recent introduction of interest 
was Euphorbia paralias along beaches. This was probably 
introduced on boats, an inevitable event in view of its 
widespread distribution along the mainland coast south 
of Perth (Keighery & Dodd 1997). 
The native Anthocercis littorea was recorded on 
Rottnest Island for the first time after a fire in 1997. Its 
seeds are hardcoated and can remain dormant until 
fire or disturbance of the soil cause germination 
(Powell & Emberson 1981; Haegi el al. 1982), yet this 
very conspicuous perennial species was not recorded 
during the botanical surveys after the 1955 fire, which 
included the site of the present specimen (500 m west 
of Barker Swamp). Birds are probably not responsible 
for bringing its seeds to the island, as the capsules are 
dry and the seeds are small, making them more suited 
to insect dispersal (L Haegi, Royal Botanic Gardens, 
Sydney, personal communication). It is possible that 
the seeds of this species have remained viable in the 
soil for many decades. Whatever its origin, this one 
plant is a true 'first record' for Rottnest of a coastal 
species that is common on the mainland (Rippey & 
Rowland 1995). 
Acknowledgements: This study is based on the Rottnest Island Herbarium 
collected by members of the Rottnest Voluntary Guides Association and 
this paper is presented by the authors on behalf of all Rottnest Voluntary 
Guides. We are grateful to the Rottnest Island Authority for their support 
and in particular to Claire Wright and Chas Hansen. The WA Herbarium 
made the project possible by providing facilities under their Community 
Regional Herbaria Volunteer Program. Particular thanks are also due to 
Dr Patrick Armstrong for his helpful comments. 
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