70 



COROLLA. 



Each simple part, of which the corolla is composed, is called a 

 fetal. A flower with petals is said to be petalous ; without petals, 

 apetalous. The petals are said to be definite, wlien their number is 

 not more than twenty, indefinite, when they exceed that number. 



If the corolla is formed of one single piece, or petal, it is monopet- 

 alous ; if of more than one, it is polypetalous. You may sometimes 

 find a difficulty in determining whether a corolla is composed of one 

 piece or more ; for monopetalous flowers often have deep divisions, 

 extending almost to the base of the corolla; but they must be divi- 

 ded at the base ; that is, be in separate pieces, in order to be consid- 

 ered poZy/ie^a/oifs. The parts into which a corolla naturally falls, 

 may be considered as so many petals. 



Monopetalous coi-ollas, (see Fig. 70.) consist of the tube, throat, and 

 limb. The tube is the lower part, having more or less the form of a 

 tunnel. The throat is the entrance into the tube ; it is either open, 

 or closed by scales or hairs. The limb is the upper border of the co- 

 rolla. 



Polypetalous corollas consist of several petals. 

 Each petal consists of two parts, the lamina, 

 and claio. 



The lamina, (Fig. 69, a,) is the upper, and 

 usually the thinner part of the petal ; its margin 

 is sometimes entire, or without divisions, as in 

 the rose ; sometimes notched, or crenate, as in 

 the pink. The lamina corresponds to the limb 

 of monopetalous corollas. 



The claiD, (Fig. 69, b,) is the lower part of the 

 petal, and inserted upon the receptacle ; it is 

 sometimes very short, as in the rose ; in the 

 petal of the pink, as seen at Fig. 69, it is long 

 and slender. The claw is analogous to the tube 

 of monopetalous corollas. 



The corolla is superior when inserted above 

 the germ, inferior, when below. It is regular, when each division 

 corresponds to the other. The rose and pink have regular corollas. 

 When the parts do not correspond with each other, a corolla is ir- 

 regtdar; as in the pea and the labiate flowers. 



> 

 Different forvis of Monopetalous Corollas. 



Fig. 70. Monopetalous corollas may, according to 



their forms, be divided as follows : 



1st. Bell-form, (campanulate, from campanu- 

 la, a little bell ; here the tube is not very dis- 

 tinct, as the corolla gradually spreads from the 

 base ; as in the blue-bell, hair-bell, &c. At Fig. 

 70, is the representation of a bell-form corolla; 

 It is monopetalous ; the limb, a, is five-parted j 

 calyx, b, five-parted ; corolla superior. The 

 blue-bell of the gardens oflfers a fine illustra- 

 tion of this kind of corolla. 



Fig. 69. 



Parts of the corolla— Polypetalous corollas, how divided ?— Forms of monopeta- 

 lous corollas— Polypetalous— Corolla, superior— Inferior— Regular —Irregular—Bell • 

 form. 



