44 



Position and 

 Number of 

 Parts of the 

 Flower. 



corolla is also said to be toothed when the sepals or petals 

 are united nearly to the apex, deft, or lobed, if divided to 

 about the middle, and parted if divided nearly to the base. 

 The same terms may also be used for the perianth. 



40. When both calyx and 



corolla are present the number of sepals is very frequently 

 equal to the number of petals. The organs of the flower are 

 usually inserted in whorls on the receptacle ; the internodes 

 between the whorls being as a rule very short, the whorls are 

 all brought close together and the members of successive whorls 

 are seen to alternate with each other. Thus we find an outer 

 whorl of say 5 sepals and then, inside and above them on the 

 receptacle, a whorl of 5 petals so arranged that each petal 

 stands in the gap between two sepals, then inside the petals 

 a whorl of 5 stamens alternating with the petals and each 

 stamen therefore opposite a sepal, then another and inner 

 whorl of stamens alternating with the outer and each of its- 

 stamens therefore opposite a petal, and finally the pistil, or 

 pistils. Some flowers have a whorl of bracteoles outside the 

 calyx, which at first sight may be mistaken for an extra whorl 

 of sepals. By carefully counting the obvious petals and sepals, 

 however, their true nature may usually be detected. Thus in a 

 flower of Hibiscus Rosa-sinensis we find, outside the stamens, 

 5 large red obvious petals and then a gamosepalous calyx of 5 

 connate sepals alternating with them. In addition to these, 

 however, we find 6 or 7 linear bracteoles. If the latter formed 

 a normal whorl of sepals they would be 5 in number alternating 

 with the whorl above, which they do not, but even if they 

 were 5 in number and did correctly alternate with the sepals 

 above them, by including them among the sepals the latter 

 would become twice as numerous as the petals, which is unusual. 

 Again in the cotton plant (Gossypium) we find an obvious, 

 corolla outside the stamens composed of 5 large yellow petals 

 with a purple centre and a gamosepalous calyx of 5 connate 

 sepals and then 3 large leafy bracteoles j ust below the calyx. 

 One or more whorls of bracteoles which in this way resemble 

 an outer calyx of a single flower form what is called an 

 epicalyx and remind us of the so-called involucre of bracts at 

 the base of a head or umbel of several flowers. 



What has been just said must of course not be taken to 

 mean that in a flower, in which both calyx and corolla are 

 present, the number of sepals must equal the number of petals 

 and the members of each whorl must alternate with those of the 

 next, as there are obviously several flowers in which this is not 



