68 BOTANY FOR BEGINNERS. [Ch.XIL 



CHAPTER XII. 



Corolla. Nectary. 



271. THE term corolla, or corol, is derived from the Latin, 

 corolla, a little crown or chaplet. As the calyx is formed by a 

 continuation of the fibres of the outer bark, the corolla is a con- 

 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 coloui, 

 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 scsJes 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 it is perfectly easy to distinguish them. The colour 

 usually constitutes a very striking mark of difference j 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. Each 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 potypelalQUs. You 



271. What is the corolla'? 



272. What is observed of the various colours of the corolla 1 



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 term* 

 which express them 1 



?~ What is meant by the terms monopetalous and polypetalous? 



