Ch. XIII] 



THE DICOTYLEDONS 



543 



transitional form being the Dorstenia or open fig, grown in 

 greenhouses. Here belong also the Banyan (Fig. 178), and the 

 familiar Rubber Plant grown in houses. The latter is one of 

 several plants which yield the invaluable rubber from their 

 milky juice (page 108). Members of this family form the 

 prominent ' ' strangling figs " 

 of the Tropics (Fig. 385). 

 Here also belongs the famil- 

 iar Hop vine, the Hemp — a 

 tall herb producing a tough 

 fiber, now largely super- 

 seded by Manila hemp 

 (page 538), and the Nettles, 

 with their stinging hairs 

 and excellent fine fibers. 



Order 8. Santalales : 

 the Sandalwoods and 

 Mistletoes. About 1000 

 species, chiefly tropical, of 

 shrubby plants, with rather 

 simple flowers, but inter- 

 esting because including a 

 great many parasites. The 

 Sandalwoods, known for 

 their aromatic wood, are 

 half-parasitic on roots in the 

 ground in the same manner 

 as are Mistletoes on trees, 

 viz., they have chlorophyll and form their own food, taking 

 only water and mineral salts from the host (page 86 ; Fig. 386). 

 Many, however, notably in the family Loranthacece, become 

 complete colorless parasites, exhibiting striking adaptations 

 to their special modes of life (Fig. 387). A form of our own 

 woods (Arceuthobium), produces a form of Witches' Broom, 

 much like those developed by Fungi (page 198). 



Fig. 385. — A Strangling Fig, Ficns 

 ligustrina, in process of development 

 on a Palmetto ; greatly reduced. (After 

 Trelease.) 



