90 MoRPriOLOGV 



and perigynous flowers there seems At first Sight to 

 be a departure from the acropetal order of growth of 

 the floral leaves, but that this departure is only ap- 

 parent and not real will appear from what has been 

 stated above. 



The use of the term perianth has already been 

 explained. It is said to be polyphyllous (many- 

 leaved) when the segments are free, and gamophyl- 

 Lous (one-leaved) when the segments are connate. 



tt h c 



Fig-. 84. — .Estivation ol Flowers 

 a, Imbricate, h, Valvate. c, Contorted or twisted, d, VexiUary. 



The vernation of sepals and petals in a flower-bud 

 is described in very much the same terms as are used 

 in the description of the leaves in a leaf-bud. Thus 

 the petals may be: (i) valvate — b (fig. 84), as in ata, 

 nona, kantali-champa ; (2) imbricate — a, as in Mus- 

 tard and Poppy; (3) plicate, as in begoon and 

 kalmi-shag; (4) twisted or contorted— c, as in 

 jaba, natkan (Anatto), karabi, and kalika-phul; (5) 

 crumpled, as in Poppy and shial-kanta; or (6) 

 vexillary — d, as in Pea. The term vernation or 

 prefoliation is usually restricted to the description of 

 leaf-buds, and the term estivation or prefloration 

 is used in the description of flower-buds. 



