BOTANY OF TERRA AUSTRALIS. 29 



tliG dilated, and in a few cases obscurely lobed, apex: of 

 which the sessile ovarium is placed. If this be a correct 

 view of the structure of Euphorbia, it may be expected that 

 the true filament or npper joint of what has common.ly 

 been called filauient, should, as in other plants, be produced 

 subsequent to the distinct formation of the anthera, which 

 consequently will be found at first sessile on the lower 

 joint or peduncle, after that has attained nearly its full 

 length ; and accordingly this proves to be the case in snch 

 species as I have examined. Additional probability is given 

 to this view by the difference existing between the surfaces [557 

 of the two joints in some species. I consider it, however, 

 as absolutely proved by an unpublished genus of this order, 

 having an involucrum nearly similar to that of Euphorbia, 

 and like it, inclosing several fasciculi of monandrous male 

 flowers, surrounding a single female ; but which, both at 

 the joint of the supposed filament, and at that by which 

 the ovarium is connected with its pedicellus, has an obvious 

 perianthium, regularly divided into lobes. 



UjMBELLIFER^.' This order may be considered as 

 chiefly European, having its maximum in the temperate 

 climates of the northern hemisphere ; in the corresponding 

 southern parallels it is certainly much less frequent, and 

 within the tropics very few species have been observed. In 

 Terra Australis the Umbelliferoe, including a few Araliae, 

 which belong at least to the same natural class, exceed 50 

 species. The greater part of these are found in the principal 

 parallel, in which also those genera deviating most remark- 

 ably from the usual structure of the order occur. The most 

 singular of these is Actinotics of Labillardiere,~ which diftcrs 

 from the whole order in having a single ovulum in the un- 

 impregnated ovarium. A second genus, which I shall here- 

 after publish with the name of Lcucolcena, is worthy of 

 notice on account of the great apparent diflerences of inflo- 

 rescence existing amongst its species ; which agree in habit, 



« Jus. (jen. 218. 



^ Nov. Roll. 111. spec. 3, />. G7, L 92. Eriocalia, S//iil/i cxol. hut. 2, /;. 37. 



