LETTER X. 



THE MARVEL OF PERU TRIBE THE OAK TRIBE 



STRUCTURE OF DICOTYLEDONOUS WOOD. 



(Plate X.J 



So accustomed are people to identify gay colours 

 with the corolla of a flower, that it is always difficult 

 to make them believe the ovary and red striped part 

 of the Marvel of Peru, to be really a calyx. Such, 

 however, is undoubtedly the fact. 



The Marvel of Peru (Mirabilis ' Jalapa) is the re- 

 presentative of a tiibe named after it, belonging, 

 like the subjects of my last letter, to the Apetalous 

 division of Dicotyledonous plants. It has fleshy pe- 

 rennial roots ; jointed stems, which perish at the first 

 attack of frost ; and broad opposite leaves, with 

 netted veins. Its flowers appear in compact clusters ; 

 and are each surrounded at the base by a green invo- 

 lucre, divided into five segments, so as to resemble a 

 calyx, for which it would be certainly mistaken, if it 

 did not sometimes bear two flowers within the same 

 involucre ; a kind of structure that never is found in 

 a true calyx. 



Each flower consists, firstly, of a funnel-shaped 

 calyx (Plate X. l.fg. 1.), divided at the end into 

 five orange and red plaited lobes, and contracted at 



