DIV. II 



ANGIOSPERMAE 



693 



situated in the axils of the leaves and sometimes in the axils of the bracteoles of 

 another flowei'. Calystegia has two large bracteoles placed immediately beneath 

 the calyx. C. sepium. The Dodder (Cuscuta) is a slender parasitic plant con- 

 taining very little chlorophyll, which attaches itself by means of haustoria to a 



FIG. 746. Asclepiasciirassavica. A, Flower ; an,, androeceum (x 4). B, Calyx and gynaeceum 

 fn, ovary ; fc, adhesive discs (x 6). C, Pollinia (more highly magnified). (After BAILLON.) 



Fin. m.Vincetoriciun officin 

 (i nat. size). Poisoxocs. 



Fir;. 74S. Exogonium purga (% nat. size. After BERG and 

 SCHMIDT). OFFICIAL. 



number of different host plants (Fig. 221). Ipomaea : several species are cultivated 

 as ornamental plants. /. pcscaprae is one of the strand plants of tropical countries. 

 OFFICIAL. JALAPA is obtained from Exocjonium purga (Fig. 748), a twining 

 plant, with tiiberous lateral roots, occurring on the wooded eastern slopes of the 

 Mexican tableland. Ipomaea hcderacca, I. orizabcnsis, I. turpethum. SCAM- 

 MOXIAE RADIX is the dried root of Conv>:>l-cV'HS Sca/nmonm (Asia Minor). 



