454 



FO UR TH GR UP. —SEED- PL A NTS. 



are arranged in whorls, and the flowers are therefore cyclic; it is only in a com- 

 paratively small number of families, Ranunculaceae, Magnoliaceae, Calycanthaceae, 

 Nymphaeaceae, Nelumboneae, that they are all or some of them arranged spirally 

 (acyclic or hemicyclic). 



Fig. 382. Floral diagram 

 of Parnassia (Saxiifraga- 



I-IG. 3 3. Floral diafrram of Campa 

 nulaceae. A Campanula, a Lobelia. 



Fig. 381. Floral diagram 

 of Caprifoliaceae. A Leyces- 

 teria. a Lonicera. b Syni- 

 pk 



Fig. 3S7. Floral diagram of 

 some Rubiaceae. 



588. Floral diagram of 

 Plantagineae. 



lenispermaceae. 



The whorls of cyclic flowers are usually pentamerous, less frequently tetramerous, 

 and both kinds are met with in the same groups of allied plants; trimerous and 

 dimerous floral whorls or combinations of dimerous and tetramerous whorls are much 

 less common than pentamerous whorls, and are usually characteristic of smaller 

 groups in the natural system. Pentamerous or tetramerous flowers have usually 



beneath the diagrams are intended to indicate the number and cohesion of the carpels and also the 

 placentation of plants whose diagram is in other respects the same.' Sachs, IV. Ed. 



