30 GENERAL REMARKS ON THE 



in the more essential parts of fructification, and even in their 

 remarkable invohicella. Of this genus, one species has a 

 compound umbel of four many-flowered radii ; a second 

 has an umbel of three rays with two or three flowers in 

 each; several others, still retaining the compound umbel, 

 which is proved by the presence of their involucella, have 

 from four to two smgle-flowered rays : and lastly one 

 species has been observed, which is reduced to a single 

 flower ; this flower, however, is in fact the remaining soli- 

 tary ray of a compound umbel, as is indicated by the two 

 bracteae on its footstalk, of which the lower represents the 

 corresponding leaf of the general involucrum, while the 

 upper is evidently similar to the involucellum of the two- 

 rayed species of the genus. 



558] COMPOSIT^.^ Of this family, which is the most ex- 

 tensive among Dicotyledones, upwards of 2500 species have 

 been already described. About 300 are at present known 

 in Terra Australis, in which therefore the proportion of 

 Compositae to its Dicotyledonous plants is considerably 

 smaller than that of the whole order to Dicotyledones 

 generally, and scarcely half that which exists in the Mora 

 of South Africa. It is also inferior in number of species to 

 Leguminosae, like which it seems expedient to consider it as 

 a class including several natural orders. Of these orders 

 CiclwracecB and CinarocejjhalcB are comparatively very rare 

 in Terra Australis, not more than ten species of both having 

 hitherto been observed. 



The class therefore chiefly consists of CorymbifercB, Avhich 

 are very generally difl'used ; they are however evidently less 

 numerous within the tropic, and their maximum appears to 

 exist in Van Diemen's Island. Corymbiferae may be sub- 

 divided into sections and the greater part of the genera 

 peculiar to Terra Australis belong to that section which 

 may be named GnapJialoidece, and exist either in the 

 principal parallel or higher latitudes. 



The whole of Compositce agree in two remarkable points 

 • 



^ Adans.fam. 2, p. 103. Decaml. Theor. elem. 216. 



