BY BARON VON MUELLER. 21 



ridgelet, compressed towards the outer margiu and there somewhat 

 granular-rough. 



Near the eastern sources of Swan River ; Miss Alice Eaton. 



Height of the whole plant from few to several inches. Root 

 very thin, two to three inches long. Basal leaves few, of only ^-^ 

 inch measurement, so far as seen on the only two specimens 

 extant. Peduncles hollow, clubshaped-dilated, finally thickened 

 to |- inch in diameter at the summit. Petals valvate before 

 expansion. Fruit hardly ^ inch broad. 



In every instance, so far as the available material demonstrates, 

 the hollow dilatation of the peduncles occurs ; but I found no 

 insects in them, though likely the cavity would be filled with sap 

 while the plant is growing. This remarkable structure reminds of 

 what is seen thus far in Utricularia tuhulata. The aspect of the 

 plant is that of a Didiscus in miniature ; but on account of the 

 presence of stipules and want of involucre it seems preferable to 

 place this species in Hydrocotyle. 



Some difficulty has arisen in the use of the name Didiscus for 

 the genus, to which so long and so extensively it was applied. As 

 regards etymology the designation Trachymene certainly applies 

 best to Didiscus alhijiortts, but it is not altogether inapplicable to 

 the two other species, which Rudge at once included in Trachymene. 

 As Siebera among Compositse takes by one year precedence over 

 Siebera in Umbelliferse, it seems best, to resort again to the older 

 nomenclature by maintaining Didiscus for generic appellation. 

 The following are as yet unrecorded localities for Australian 

 Umbelliferae. 



Hydrocotyle Javanica, Peel-River (Musson) ; Edgecombe-Bay 

 (Birch). 



H. pedicellosa, Tambourine-Mountains (Scortechini) ; Pee 

 River (Museum) ; the leaves attain three inches in diameter. 

 //. yera7iifolia, Hawkesbury-River (Woolls). 

 H. callicarpa, Hume-River (Jephcott) ; height to six inches. 

 //. trachycarpa, Lachlan-River (Andrae). 



