BOTANY OF TERRA AUSTRALIS. 43 



are readily distinguishable from the whole order bv their 

 fructus superus, and tliey may possibly differ also in the 

 internal structure of their ovarium, which has not yet been 

 satisfactorily ascertained. 



The genus Exocarpiis is most abundant in the principal 

 parallel and southern parts of Terra Austral is, but it is not 

 unfrequent even within the tropic. Exocarpns cupre.s.si- 

 formis is not only the most common species of the genus, 

 but the most general tree in Terra Australis, being found 

 in nearly the whole of the principal parallel, in every part 

 of \\an Diemen's Island that has been visited, and even 

 within the tropic. I am acquainted with only three plants 

 that have in that country an e(iual!y extensive range. These 

 are A?ifhistiria aust rails, the most valuable grass as well as 

 the most general plant in Terra Australis ; Arundo Fhrcifj- 

 mites, less frequent than the former, but which extends 

 from the southern extremity of Van Diemen's Island to 

 the north coast of New Holland ; and Mesemhnjanthemum 

 aquilatercde, which occurs on almost every part of the 

 sandy sea shores of both these islands. 



Exocarpns is not absolutely confined to Terra Australis, for 

 ^I. Bauer has discovered a very remarkable species bearing 

 its fiow'ers on the margins of dilated foliaceous branches, 

 analogous to those of Xylophylla ; and XuJoplnjlla lonfji- 

 folia, which was taken up by Linnaeus from Rumphius,^ [570 

 appears more probably, both from the description and 

 figure of that author, to be also a species of Exocarpns. 



There is so crreat a resemblance between the enlarsfed 

 fleshy receptacle of Exocarpns and the berry of Taxus, that 

 some botanists have been led to compare these plants to- 

 gether in other respects. A complete coincidence in this 

 part of their structure would not indeed prove the affinity 

 of these tw^o genera, any more than it does that of Exo- 

 carpns to Anacardiuui or Semecarpus, with which also it 

 has been compared; and to determine their agreement 

 even in this respect it is necessary to understand the origin 

 of the berry of Taxus, of which very different accounts 



* X^lopb}llos ceraniica, llerh. amb. 7,}k 10, t. 12. 



