SECTION 8.] MODIFICATIONS OF THE TYPE. 93 



266. There are all gradations between labiate and regular corollas. In 

 those of Gerardia, of some species of Pentstemon, and of Catalpa (Fig. 

 263-265), the labiate character is slight, but is manifest on close inspection. 

 In almost all such flowers the plan of five, which is obvious or ascertain- 

 able in the calyx and corolla, is obscured in the stamens by the abortion or 

 suppression of one or three of their number. 



267. Ligulate Corolla. The ligulate or Strap-shaped corolla mainly 

 belongs to the family of Composite, in which numerous small flowers are 



gathered into a head, within an involucre that imitates a calyx. It is best 

 exemplified in the Dandelion and in Chiccory (Fig. 266). Each one of 

 these straps or Ligules, looking like so many petals, is the corolla of a dis- 



tinct flower : the base is a short tube, which opens out into the ligule : the 

 five minute teeth at the end indicate the number of constituent petals. So 

 this is a kind of gamopetalous corolla, which is open along one side nearly 



Fio. 266. Two flower-heads of CMooory. 



Fio. 267. One of them half cut away, Better showiik? some of the flo>t>-. 



