110 



MORPHOLOGY, OE COMPARATIVE ANATOMY. 



divided into lobes, as in many Caryophyllacese (fig. 186) and the 

 pinnatifid petals of Schizopttalum, &c. 





Fig. 185. 



Fig. 187. 



Fig. 186. 



Fig. 185. Petal of Dianthus, fringed and stalked. Fig. 186. Bilobed petal of Alsine media. 

 Fig. 187. Spurred petal of Aquilegia. 



Forms of Petals. The forms of petals resemble many of those 

 indicated for simple true leaves ; in addition to which others occur 

 presenting curved surfaces : these are called simply concave, navi- 

 cular or boat-shaped, cochleariform or shaped like the bowl of a 

 spoon, &c. ; or they may have basal pouches, and be gibbous, sac- 

 cate, or spurred (fig. 187). Others have peculiar appendages above, 

 such as the crests in Polygala and the strap-Like inflexed points in 

 the petals of the Umbelliferae. 



The term nectary is vaguely employed to indicate certain struc- 

 tures of varying character intermediate in position between the 

 petals and the stamens, and different in aspect from both. 



Petals are ordinarily of delicate structure and coloured, whence we 

 derive the term petaloid ; but they vary in texture from a membrana- 

 ceous to a thick and fleshy condition, such as we see in Magnolia, Nym- 

 ph&a, &c. 



Polypetalous Corollas are regular when the petals are equal 

 and symmetrically arranged; the individual petals may be them- 

 selves either symmetrical or oblique, provided they are all alike. 



Some of them have received special names, such as : the rosaceous, 

 where there are five spreading petals ; the liliaceous, where six petals 

 spread gradually from a funnel-shaped origin ; caryophyllaceous, where 

 five petals have long erect claws ffbm which the limbs turn off at a sharp 

 angle ; cruciform, where four such long-clawed petals with horizontal 

 limbs stand in the form of a cross, as in the Wallflower, &c. Slight 

 degrees of irregularity arise from some petals growing larger than others, 

 as in the case of the outer petals of the outer flowers of the corymbs of 

 Iberis, those of the umbels of Umbelliferee, &c. ; but more striking irre- 

 gularity results from unlikeness of the petals and disturbance of symme- 

 try in their insertion or point of emergence. The imperfect corolla of 



