niAi'. VI] l-'-DAIMIIC INFLUENCES IN Tin; TROPICS 401 



extensive bush)- mangrove (Fig. 222I, in which the grey foliage, often 

 jbcdecked with briglit yellow inflorescences, extends nearly to the ground. 

 Aegiceras majus is a niotlcrately 





'''''' ^i^ 



Fig. 2.' I. Sonnemtia .aciil.T. Jav.inese m.mgrove. 

 From .T photogn-ijjh by G. Karsten. 



lall shrub, and Acanthus ilici- 

 fiilius a thistle-like herb. 



The stilt-roots, which give 

 Rhizophora nuicronata such a 

 peculiar appearance, occur rela- 

 tively strongly developed else- 

 where only in the herbaceous 

 Acanthus. In Rhizophora con- 

 JLigata, which does not descend so 

 far towards the sea as does R. 

 nuicronata, they are more weakly 

 jdeveloped than in R. mucronata. 

 jlntheothcr niangrove-trccs the\' 



ii'c either absent or only slightly 

 developed (Fig. 225) ; in parti- 

 cular, the anchoring-roots de- 

 scending from the branches are 



ranting. 

 On the other hand, the roots 



if most mangrove-trees are 



haracterized by the possession 



)f highly peculiar pneumato- 



)hores (Figs. 223, 324, 225). 



These are displayed in their 



implest form byCarapa obovata 



Fig. 223, 3), where the scrpen- 



iiie creeping roots project above 

 ihe mud with their upper edge, 

 like the blade of a thick knife, 



;)ut studded with lenticels. In 



^arapa molucccnsis the secon- 



!ary growth in thickness in the 



ipper part is irregular, so that 



he root terminates in finger-like 

 growths. In the species of 



?ruguiera (Figs. 223, i and 2 ; 



25), the horizontal roots here 



nd there bend out of the mud 



ito knee-like structures, which 



1 Bruguiera gymnorrhiza bear large lenticels, but in Bruguiera caryophyl- 



ICHIMI'ER J) (^ 



Fig. 222. Avicennia officinalis at low tide. Javanese 

 mangrove. From a photograph by G. Karsten. 



