80 DICOTYLEDONE^:. 



Penecicece and Ericece embracing the greater num- 

 ber of the ornaments of our green-houses and 

 shrubberies. For delicacy as well as amplitude of 

 foliage, splendid colours, and varied form of flowers, 

 the Ericece stand unrivalled. 



A majority of the orders of this sub-class are dis- 

 tinguished from each other by botanical synonymes 

 rather than by physical differences. To enumerate 

 them is therefore unnecessary : the orders Compos ita*, 

 ftubiacece, and Umbelliferce, however, are particu- 

 larly well marked in exterior form ; but it is not till 

 we arrive at Opuntidcece that we meet with any thing 

 constitutionally different. In this last-named order 

 we find no resemblance of either herb, shrub, or tree, 

 in the common acceptation of these terms. Here we 

 see vegetable bodies of regular, as well as of most 

 grotesque forms; some of them destitute of branches, 

 and almost all of them of leaves. In Epiphyllum 

 and Opuntia, the stems are flattened to do the office 

 of leaves, and also of peduncles. The Mammilldria 



* Among the Composites we find the Elephantopus, a singular 

 production. This plant has fibrous roots and proper laxive stems 

 annually put forth. Its principal accretion is concentrated in the 

 collet, which becomes monstrous and assumes a ligneous character, 

 becoming hollow within. The bark of the tumour is increased in 

 thickness like that of trees ; and is very regularly fractured by the 

 annual growth. 



These annual growths are pretty distinctly marked in the bark : 

 and by which the age of the plant may be calculated with great 

 certainty. Some individual plants have been seen at the Cape of 

 Good Hope above two hundred years old. 



