Ch. XIL.} THE COROLLA. 69 
may sometimes find a difficulty in determining whether the co- 
rolla is in one piece or more; for monopetalous flowers often have 
deep divisions, extending almost to the base of the corolla; but 
a corolla must be divided at the base, or be in separate pieces, 
in order to be considered as polypetalous. It is a good rule to 
consider the parts into which a corolla naturally falls,.as so 
many petals. 
277. Monopetalous corollas (see Fig. 44,) consists of the tube, 
throat, and limb. The tube, is the lower part, having more or 
less the form of a tunnel. The ¢hroat is the entrance into the 
tube; itis either open, or closed by scales or hairs. The limb 
is the upper border of the corolla. 
Fig. 43. 278. Polypetalous corollas consist of 
several petals. Each petal consists of 
two parts, the /amina and claw. 
279. The lamina, (Fig. 48, a) is the 
upper and usually thinner part of the pe- 
tal; its margin is sometimes entire, or 
without divisions, as in the Rose; some- 
times notched, or crenate, as in the Pink. 
The lamina corresponds to the limb of 
monopetalous corollas. 
280. The claw (Fig. 43, b,) is the lower 
part of the petal, and inserted upon the 
receptacle; it is sometimes very short as 
in the Rose; in the Pink, as seen at Fig. 
43, itis long and slender. The claw is 
analogous to the tube of monopetalous corollas. 
_ 281. The corolla is superior when it is inserted above the 
germ; inferior, when below. It is regular when each divi- 
sion corresponds to the other. The Rose and Pink have regular 
corollas. When the parts do not correspond with each other, a 
corolla is irregular, as in the Pea and Violet. 
i 
Different forms of Monopetalous Corollas. 
Monvpetalous corollas may, according to their forms, be di- 
vided as follows; 
277. What are the parts of a monopetalous corolla? 
278. What are the parts of a polypetalous corolla? 
279. What is the lamina ? 
280. What is the claw ? 
_ 281. What is meant by the terms inferior and superior, regula 
and irregular, when applied to the corolla ? 
