68 BOTANY FOR BEGINNERS. (Ch. Xi1. 
CHAPTER XIU. 
Coroila.— Nectary. 
71. Tue term corolla, or corol, is derived from the Latin, 
verolla, a little crown or chaplet. As the calyx is formed by a 
continuation of the fibres of the outer bark, the corolla is a cun- 
tinuation of the cellular integument, or inner coat of the same. 
The texture of the corolla is delicate, soft, watery, and coloured. 
The cuticle, or outward covering, of the corolla is of an extreme- 
ly fine texture. The rich and variegated colours of flowers, are | 
owing to the delicate organization of the corolla; and to this 
cause, its transient duration may also be attributed. 
272. The corolla exhibits every variety of colour, except 
black ; florists sometimes present us with what they term black 
roses, and we see some other flowers which approach this colow, 
yet none are perfectly black; the darkest being but'a very deep 
shade of purple. Corollas are white, yellow, blue, violet, &c.;. 
in some, different colours are delicately shaded and blended ; 
in others, they meet abruptly, without any intermediate tint. 
273. The corolla, before blossoming, is folded in the calyx, 
as the leaves are within the scales of the leaf-bud, and the 
whole is then called the flower-bud. . 
274. In most cases, the calyx and corolla are so distinctly 
marked, that itis perfectly easy to distinguish them. The colour 
usually constitutes a very striking mark of difference ; the calyx 
being ordinarily green, and the corolla of a more lively hue, but 
the colour is not always a criterion. In some cases, the calyx is 
beautifully coloured. 
- 275. Kach simple part, of which the corolla is composed, is 
called a petal. A flower with petals is said to be petalous ; 
without petals, apetalous. The petals are definite, when their 
number is not more than twenty ; indefinite when they exceed 
that number. 
276. If the corolla is formed of one single piece, or petal, it 
is monopetalous ; if of more than one, it is polypetulous. You 
271. What 1s the corolla? 
272. What is observed of the various colours of the corolla? 
273. Where is the corolla before blossoming ? 
274. How are the calyx and corolla distinguished 
275. What is said of the divisions of the corolla, and the terms » 
which express them ? 
2°6. What is meant by the terms monopetalous and polypetalous ? 
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