BALANOPHORA: CYTINUS 



233 



Maltese Sponge, growing on halophytic shrubs in the 

 Mediterranean region. The vegetative body consists of 

 large branched tubers attached to the roots of the host. 

 From it arise massive, club-shaped or globular, often 

 branched inflorescences with scale leaves, and many flowers, 

 frequently brilliant in colouring. 



Even in young stages there is no differentiation of root 

 and shoot. The tuber may be in contact with several host 

 roots, which it enve- 

 lops. No suckers are 

 produced. The host 

 root, the cortex of which 

 is resorbed, sends 

 branching extensions of 

 vascular tissue into the 

 parasitic tuber, and even 

 into the inflorescences. 

 We have here a case 

 in which the union of 

 parasite and host is 

 mutual and extremelv 

 intimate ; the tuber is, 

 in a way, a joint organ 

 (Fig. 24, 2). 



The Hydnoraceas 

 and Rafflesiaceae are 

 also characteristically 

 tropical famiUes. One 

 species, Cytinus hypo- 

 cistis (Rafflesiaceae) is 

 parasitic on roots of 



Cistus shrubs in the Mediterranean and southern Atlantic 

 coastal regions of France (Fig. 27). The Hydnoraceae 

 possess branching rhizomes which make connection with 

 the roots of the host apparently after the fashion of the 

 broom-rapes. From these arise several solitary leathery or 

 fleshy flowers (Fig, 28). 



The flower of the Rafflesiaceae is also usually solitary. 



AJ^'D 



Fig. 28 



Hydnora africana, single flower 

 rising from the thick rhizome-like 

 vegetative body. Nat. size. 



