i66 



Fam. II. Loranthaceae. 

 (Plates 38, 39.) 



Shrubby, chlorophyll-bearing sem i- parasites, 

 with expanded or rudimentary leaves, living on trees or 

 shrubs. 



Flowers regular, but very different in the two South 

 African genera. Ovary inferior, immersed in the enlarged 

 receptacle. In the central tissue of the ovary (corre- 

 sponding to a rudimentary placenta) several embryo- 

 sacs originate, but generally one only develops into an 

 embryo, rarely 2 or 3. Fruit a berry-like pseudocarp, 

 formed by the fleshy receptacle, the pericarp (sometimes 

 mistaken for a testa), the fleshy endosperm and the 

 embryo. The cotyledons contain chlorophyll. 



The inner layer of the receptacle becomes trans- 

 formed into a viscid mass, called viscin, by means of which 

 the seeds easily adhere to the beaks of birds when these 

 eat the fruit ; they are then attached to the branches of 

 shrubs or trees by the bird in his endeavours to get rid of 

 them, hence the colonial name "vogelent." The embryo 

 germinates on the branch, and when the rootlet touches 

 the bark, it develops a disc from which strands of thallus 

 enter the bark and spread in the young wood*. [See green 

 parts on Plate 38, C, 1.] The parasite does not draw assimi- 

 lated food from the host but only water and mineral 

 matter, appropriating the rising sap for its own work of 

 assimilation, and thus it deprives the upper end of the 

 branch, on which it perches, of the necessary supplies, 

 thereby often killing it. It is sometimes said that the seed 

 must have passed through the intestines of a bird before 

 it is able to germinate, but one often finds germinating 

 embryos in the unopened fruit. {Continued on page 169.) 



* In the case of Vncum minimum no huils originate from the disc, but the strands of 

 thallus within the stem of the Euphorbia produce little shoots, which penetrate the 

 epidermis here and there. The parasite remains embedded in the body of the host, and 

 only the flowers appear at the surface. 



