62 



PART I. — ORGANOGRAPHY. 



also, there are several modifications. The equitant, half-equitant 

 and triquetrous have already been described. 



The quincuncial \% that form in which there are five pieces, 

 two entirely external, two entirely internal, and the remaining one 

 having one edge external and one internal, as shown in the first 

 or outer whorl of Fig. 199. The vexillary is the variety observed 

 in the corollas of the Pea and many other members of the Pulse 



Fig. 199 



Fig. 199. — Diagram. The outer whorl represents quincuncial, the inner one, contorted 

 prefloration. 



Fig. 200. — Diagram of plicate prefloration of the Harebell. 

 Fig. 201. — Diagram of supervolute prefloration of Stramonium. 



family, in which there are two lower petals overlapped by two 

 lateral ones, which in turn are overlapped by the larger upper 

 one. 



3. The Contorted Prefloration is that in which the parts are 

 arranged with one edge invariably exterior and the other interior, 

 giving to the bud a twisted appearance, as in the inner whorl, 

 Fig. 199. 



4. The Plicate or Plaited Prefloration. These terms, except 

 when applied to the folding of a single leaf or floral organ, have 

 reference only to those corollas or calyxes whose pieces are 

 united. Such an organ folded lengthwise is called plicate, as 

 the corolla of the Harebell, Fig. 200. In case the organ is both 

 folded and twisted, as in the corolla of Stramonium, Fig. 201, it 

 is commonly called supervolute. 



