BOTANY OF TERRA AUSTRALIS. 53 



different texture ; in all these respects it approaches to 

 Cjperaceae, with some of whose genera it has even a cer- 

 tain resemblance in habit. 'J'liis genus has usually been 

 found only within the tropics, but in New Holland it 

 extends as far as 33° S. lat. 



Fhihjdrum, which I have annexed to JuncCcC, has always 

 appeared to me an insulated genus, yet though not re- 

 ferable to any established natural order, it may be com- 

 pared with several in certain respects. In the structure of 

 its stamina it may in one point of view be said to be in- 

 termediate between Scitaminea* and Orchideae ; in that of 

 its pericarpium and even of its seeds it has some affinity to 

 the Latter order ; yet it differs from both of them in almost 

 every other respect. In general appearance, it bears a 

 considerable resembLance to Cartonema, which belongs to 

 Commelinea3. In some parts of its structure it may be 

 compared with Xyris, and perhaps with Burmannia; a 

 genus which I have likewise annexed to Juncene, but whose 

 real affinities are equally obscure. 



Fliilydrum pui/mceum differs in so many respects from 

 P, lanurjinosum that it may probably hereafter be con- 

 sidered as a distinct genus ; and a very few additions to 

 this tribe of plants would sanction their formation into a 

 separate natural order. 



RESTIACE/E. The principal character distinguish- [579 

 ing this family from Junceoc and Cyperaceao consists in its 

 lenticular embryo being placed at the extremity of the 

 seed opposite to the umbilicus ; from Jimcece it also differs 

 in the order of suppression of its stamina, which when re- 

 duced to three are opposite to the inner lacinicC of the 

 perianthium ; and most of its genera are distinguishable 

 from both these orders as well as fj'om Commelinc.T by 

 their simple or unilocular anthcrac. 



With the exception of Eriocaulon, Tonina, aiul Xyris, 

 the order appears to be confined to the I^outhcrn henn"- 

 sphere. In Terra Australis its maximum is in the ])rinci- 

 pal parallel, but it extends to the southern extremity of 

 Van Diemen's Island, where it is even in considerable 



