504 DJCOTYLEDONES. 



542 A, &), and then terminates its growth, if it does not produce an inflorescence ; 

 new lateral shoots proceed from the axils of the foliage-leaves, and the branch- 

 ing, in consequence, is extremely regular and falsely dichotomous. Only one 

 internode (shoot-generation) is formed each year, so that each fork indicates 

 one year. The foliage-leaves fall off in the second year. The inflorescence is 

 a 3 (-5) -flowered dichasium (Fig. 542 A, m is the central flower, n the lateral). 

 The plants are dioecious; the $ -flower as a rule is 2-merous : perianth 

 2 + 2, each leaf of which bears on its inner side 6-20 pollen-sacs, each of 

 which opens by a pore ; this relationship may be considered to have arisen 

 from the union of the perianth-leaves with the multilocular stamens (2 + 2) 

 placed opposite them. The $ -flowers always have Pr 2 + 2, G2. Loran- 

 thus is also found in Europe (it has a 3-merous flower), especially in the 

 central and south-eastern districts, on Quercus cerris and Q. pu^escens; but 

 the great majority of the 520 species grow in the Tropics on trees which they 

 ornament with their often brightly-coloured flowers, and ultimately kill when 

 present in too great numbers. The pollination in the numerous Loranthaceae 

 with unisexual flowers, is effected by the wind. In Viscum album this takes 

 place in autumn, the actual fertilisation in the following spring, and the 

 maturity in November or December ; in the succeeding month of May the 

 berry is ready to germinate, and falls off. 

 USES. Birdlime from Viscum album. 



Order 4. Rafflesiaceae and Order 5. Balanophoraceae. These orders com- 

 prise root-parasite*, almost entirely devoid of chlorophyll ; they are reddish or 

 yellow, without foliage-leaves (Fig. 543). As far as our knowledge of these rare 

 tropical plants extends, they have thalloid organs of vegetation resembling the 

 root-like strands of Viscum, or they are filamentous and branched like Fungus- 

 hyphae ; they live in and on the tissues of the host-plant, from which their 

 flowering- shoots, often of mushroom-like form, are subsequently developed 

 (Fig. 543). In order to unfold they must often break through the tissues of 

 the host-plant. 



Of the BAFFLESIACE^E, Cytinus hypocistus is found in S. Europe living on roots 

 of Cistus -plants and to some extent resembling Honotropa (Fig. 543). Rafflesia 

 is the best known ; it lives on roots of Ciasus-species (belonging to the Ampe- 

 lidacese) in Java ; its yellowish-red, stinking flowers attain a gigantic size (one 

 metre or more in diameter), and are borne almost directly on the roots of the 

 host-plant. Besides these there are other genera : Bruf/mannia, Pilostyles, 

 Hydnora. To BALANOPHORACE^ (Fig. 543) belong : Balanophora, Langsdorffia, 

 Scybalium, Sarcophyte, Helosis, etc., and in S. Europe, Cynomorium coceineunu 



Sub-Class 2. Sympetalae. 



The characters which separate this from the first Sub-class, th& 

 Choripetalce, have been described on page 336. They consist in 

 the following : the flower is always verticillate, generally with 5. 

 sepals, 5 petals, 5 stamens, and 2 carpels (in the median plane), 

 the calyx is generally persistent and gamosepalous, the corolla is 

 gamopetalous and united to the stamens, which are therefore 



